Articoli di riviste sul tema "External signal"
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1
Lacefield, Soni, e Nicholas Ingolia. "Signal Transduction: External Signals Influence Spore-Number Control". Current Biology 16, n. 4 (febbraio 2006): R125—R127. http://dx.doi.org/10.1016/j.cub.2006.02.005.
2
Ling, Yunzhi. "Design and implementation of an analog signal isolation conditioning circuit". Journal of Physics: Conference Series 2338, n. 1 (1 settembre 2022): 012071. http://dx.doi.org/10.1088/1742-6596/2338/1/012071.
Abstract (sommario):
Abstract In control systems, external analog signals need to be converted into digital signals. When sampling external input analog signals, such as voltage or current, it is necessary to process the small analog signal amplification or large signal reduction to the digital signal that can be sampled normally by the ADC; at the same time, the complexity of the external environment will affect the accuracy of sampling, and the input and output isolation processing needs to be carried out. Therefore, in order to solve the problem of low sampling accuracy of analog signal ADC in complex environment, this paper proposes an analog signal isolation conditioning circuit, which can filter out the high-frequency noise in the input signal without affecting the rapid sampling of the ADC, and use two-stage operation amplification to perform gain and zero compensation processing, so that the conditioned signal has high accuracy, good linearity, and strong anti-interference ability, which meets the design requirements. Through functional and stress tests, the functional correctness and performance stability of the analog signal isolation conditioning circuit proposed in this paper are verified.
3
Li, Ya Ping, Pin Wang e Qian Shu Li. "Controlling of explicit internal signal stochastic resonance by external signal". Journal of Chemical Physics 121, n. 12 (22 settembre 2004): 6021–25. http://dx.doi.org/10.1063/1.1783875.
4
Li, Xianfeng, Sen Xu e Xiaopeng Hua. "Pattern Recognition of Grating Perimeter Intrusion Behavior in Deep Learning Method". Symmetry 13, n. 1 (6 gennaio 2021): 87. http://dx.doi.org/10.3390/sym13010087.
Abstract (sommario):
An intrusion behavior recognition method based on deep learning is proposed in this paper in order to improve the recognition accuracy of raster perimeter intrusion behavior. The Mach–Zehnder fiber optic interferometer was used to collect the external vibration signal sensing unit, capture the external vibration signal, use the cross-correlation characteristic method to obtain the minimum frame length of the fiber vibration signal, and preprocess the intrusion signal according to the signal strength. The intrusion signals were superimposed and several sections of signals were intercepted by fixed window length; the spectrum information is obtained by Fourier transform of the intercepted stationary signals. The convolution neural network was introduced into the pattern recognition of the intrusion signals in the optical fiber perimeter defense zone, and the different characteristics of the intrusion signals were extracted, so as to realize the accurate identification of different intrusion signals. Experimental results showed that this method was highly sensitive to intrusion events, could effectively reduce the false alarm rate of intrusion signals, and could improve the accuracy and efficiency of intrusion signal recognition.
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HOLZHÜTTER, HERMANN-GEORG, e JÖRN QUEDENAU. "MATHEMATICAL MODELLING OF CELLULAR RESPONSES TO EXTERNAL SIGNALS". Journal of Biological Systems 03, n. 01 (marzo 1995): 127–38. http://dx.doi.org/10.1142/s0218339095000125.
Abstract (sommario):
An empirical mathematical model is proposed to describe the response (growth rate, metabolic activity etc.) of a cell population to various intensities of an external signal (hormone, antibody, pharmacon etc.). The model is based on the assumption that the signal causes the target system to pass consecutively through i=1, …, N distinct population states having response coefficients Ri. Describing the interaction of the system with the signal according to the rules of chemical kinetics by two phenomenological parameters (k - sensitivity, n - cooperativity index) one arrives at a series expansion for Ri which is linear in the Ri’s but nonlinear with respect to k and n (“R-decomposition”). The pattern of expansion coefficients Ri is characteristic of a given signal and can be used to reveal similarities in the responses of the cell population to various signals. A user-friendly microcomputer program has been developed to fit the model equation to experimental data by means of constraint nonlinear regression analysis and to determine all characteristic curve parameters (number and location of extremal values, inflection points etc.). The robustness and benefit of the model is demonstrated by applications to various types of “exotic” dose-reponse-curves obtained from a neutral-red assay of fibroblasts. Similarities between response curves are studied.
6
Abeysekera, Indra. "Signalling external capital disclosure in annual reports". Corporate Ownership and Control 11, n. 4 (2014): 193–202. http://dx.doi.org/10.22495/cocv11i4c1p4.
Abstract (sommario):
Much of the discussion of voluntary disclosure of external capital in annual reports entails only limited examination as signals for capital accumulation. Using the method of content analysis, this paper examines the signalling of external capital disclosure practices, the most disclosed category of intellectual capital, in annual reports of a sample of listed firms in Sri Lanka, a developing nation. Eleven case study interviews from the sample firms explore the role of signal for capital accumulation. Findings reveal that signals differ between industry sectors in convincing stakeholders to advance capital accumulation
7
Carneiro, Mirella, Victor Oliveira, Fernanda Oliveira, Marco Teixeira e Milena Pinto. "Simulation Analysis of Signal Conditioning Circuits for Plants’ Electrical Signals". Technologies 10, n. 6 (25 novembre 2022): 121. http://dx.doi.org/10.3390/technologies10060121.
Abstract (sommario):
Electrical signals are generated and transmitted through plants in response to stimuli caused by external environment factors, such as touching, luminosity, and leaf burning. By analyzing a specific plant’s electrical responses, it is possible to interpret the impact of external aspects in the plasma membrane potential and, thus, determine the cause of the electrical signal. Moreover, these signals permit the whole plant structure to be informed almost instantaneously. This work presents a brief discussion of plants electrophysiology theory and low-cost signal conditioning circuits, which are necessary for the acquisition of plants’ electrical signals. Two signal conditioning circuits, which must be chosen depending on the signal to be measured, are explained in detail and electrical simulation results, performed in OrCAD Capture Software are presented. Furthermore, Monte Carlo simulations were performed to evaluate the impact of components variations on the accuracy and efficiency of the signal conditioning circuits. Those simulations showed that, even after possible component variations, the filters’ cut-off frequencies had at most 4% variation from the mean.
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Bassilana, Martine, Charles Puerner e Robert A. Arkowitz. "External signal–mediated polarized growth in fungi". Current Opinion in Cell Biology 62 (febbraio 2020): 150–58. http://dx.doi.org/10.1016/j.ceb.2019.11.001.
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Li, Yang, e Zhiguo Tang. "Multi-terminal Detection and Localization of Partial Discharge in Transformer". Journal of Physics: Conference Series 2290, n. 1 (1 giugno 2022): 012013. http://dx.doi.org/10.1088/1742-6596/2290/1/012013.
Abstract (sommario):
Abstract The transformer is the key equipment in the power system, and partial discharge is the main reason for the deterioration of the insulation of the transformer. The existing partial discharge detection method cannot determine whether the discharge comes from the transformer body or the peripheral equipment of the transformer when the discharge signal is detected. In order to study the difference between the internal and external partial discharges of the transformer received signals at the detection end and form an effective positioning method, this paper injects high frequency small signals into the external leads, inside the windings and surrounding screens of the 110kV three-phase double-winding transformer to simulate the external discharge of the transformer, the discharge inside and outside of the windings. The research shows that the first wave polarity of the external discharge and the internal non-winding discharge of the transformer is the same at each detection terminal, and the first wave polarity of the winding discharge signal at each detection terminal is different. The polarity information can be used to judge whether the winding discharges; the external discharge is the same as the transformer internal discharge. Non-winding discharge has different proportions of high-frequency and low-frequency components in each detection terminal signal. The signal energy of each detection terminal of external discharge is concentrated in low frequency, and the signal energy of each detection terminal of non-winding discharge inside the transformer is concentrated in high frequency, which can be judged by frequency domain information. The external discharge and the internal non-winding discharge of the transformer provide a reference for the research on the multi-terminal detection and positioning of the transformer.
10
Gelenbe, Erol. "Random Neural Networks with Negative and Positive Signals and Product Form Solution". Neural Computation 1, n. 4 (dicembre 1989): 502–10. http://dx.doi.org/10.1162/neco.1989.1.4.502.
Abstract (sommario):
We introduce a new class of random “neural” networks in which signals are either negative or positive. A positive signal arriving at a neuron increases its total signal count or potential by one; a negative signal reduces it by one if the potential is positive, and has no effect if it is zero. When its potential is positive, a neuron “fires,” sending positive or negative signals at random intervals to neurons or to the outside. Positive signals represent excitatory signals and negative signals represent inhibition. We show that this model, with exponential signal emission intervals, Poisson external signal arrivals, and Markovian signal movements between neurons, has a product form leading to simple analytical expressions for the system state.
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Aditya, K., Ganesha Udupa e Yongkwun Lee. "Development of Bio-Machine Based on the Plant Response to External Stimuli". Journal of Robotics 2011 (2011): 1–7. http://dx.doi.org/10.1155/2011/124314.
Abstract (sommario):
In the area of biorobotics, intense research work is being done based on plant intelligence. Any living cell continuously receives information from the environment. In this paper, research is conducted on the plant nameddescoingsiixhaworthioides(Pepe) obtaining the action potential signals and its responses to stimulations of different light modes. The plant electrical signal is the reaction of plant’s stimulation owing to various environmental conditions. Action potentials are responsible for signaling between plant cells and communication from the plants can be achieved through modulation of various parameters of the electrical signal in the plant tissue. The modulated signals are used for providing information to the microcontroller’s algorithm for working of the bio-machine. The changes of frequency of action potentials in plant are studied. Electromyography (EMG) electrodes and needle-type conductive electrodes along with electronic modules are used to collect and transform the information from the plant. Inverse fast Fourier transform (IFFT) is used to convert signal in frequency domain into voltage signal for real-time analysis. The changes in frequency of the plant action potentials to different light modes are used for the control of the bio-machine. This work has paved the way for an extensive research towards plant intelligence.
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Sanger, Terence D. "Decoding Neural Spike Trains: Calculating the Probability That a Spike Train and an External Signal Are Related". Journal of Neurophysiology 87, n. 3 (1 marzo 2002): 1659–63. http://dx.doi.org/10.1152/jn.00121.2001.
Abstract (sommario):
Experimental and clinical applications of extracellular recordings of spiking cell activity frequently are used to relate the activity of a cell to externally measurable signals such as surface potentials, sensory stimuli, or movement measurements. When the external signal is time-varying, correlation methods have traditionally been used to quantify the degree of relation with the neural firing. However, in some circumstances correlation methods can give misleading results. A new algorithm is described that estimates the extent to which a spike train is related to a continuous time-varying signal. The technique calculates the probability of generating a spike train with Poisson statistics if the time-varying signal determines the Poisson rate. This is accomplished by successive division of the signal and the spike train into halves and recursive calculation of the probability of each half-signal. The performance of the new algorithm is compared with the performance of correlation methods on simulated data.
13
Shelishiyah, R., M. Bharani Dharan, T. Kishore Kumar, R. Musaraf e Thiyam Deepa Beeta. "Signal Processing for Hybrid BCI Signals". Journal of Physics: Conference Series 2318, n. 1 (1 agosto 2022): 012007. http://dx.doi.org/10.1088/1742-6596/2318/1/012007.
Abstract (sommario):
Abstract The brain signals can be converted to a command to control some external device using a brain-computer interface system. The unimodal BCI system has limitations like the compensation of the accuracy with the increase in the number of classes. In addition to this many of the acquisition systems are not robust for real-time application because of poor spatial or temporal resolution. To overcome this, a hybrid BCI technology that combines two acquisition systems has been introduced. In this work, we have discussed a preprocessing pipeline for enhancing brain signals acquired from fNIRS (functional Near Infrared Spectroscopy) and EEG (Electroencephalography). The data consists of brain signals for four tasks – Right/Left hand gripping and Right/Left arm raising. The EEG (brain activity) data were filtered using a bandpass filter to obtain the activity of mu (7-13 Hz) and beta (13-30 Hz) rhythm. The Oxy-haemoglobin and Deoxy-haemoglobin (HbO and HbR) concentration of the fNIRS signal was obtained with Modified Beer Lambert Law (MBLL). Both signals were filtered using a fifth-order Butterworth band pass filter and the performance of the filter is compared theoretically with the estimated signal-to-noise ratio. These results can be used further to improve feature extraction and classification accuracy of the signal.
14
Niittymäki, Jarkko, e Matti Pursula. "Saturation Flows at Signal-Group-Controlled Traffic Signals". Transportation Research Record: Journal of the Transportation Research Board 1572, n. 1 (gennaio 1997): 24–32. http://dx.doi.org/10.3141/1572-04.
Abstract (sommario):
The main goal of this research was to update the basic saturation flow values of signalized intersections. The secondary goal was to analyze the effects of certain external factors (such as weather, road, and traffic conditions) on saturation flow. The updating is based on extensive field measurements and simulations. Altogether, about 39,000 queues were observed in this study. Field measurements at 30 locations were made according to the method described in the Highway Capacity Manual and simulations were done with the Helsinki University of Technology HUT-SIM simulator, which was calibrated and carefully validated for Finnish road conditions. A summary of calibration parameters is also presented. The new base value for straight-through lanes is 1, 940 vehicles per hour; the previous value was 1, 700 vehicles per hour. In general, the updated saturation flow values of different lane types are 5 to 20 percent larger than the previous base values. The saturation flow models of different lane types are described. The effects of geometric and traffic composition factors, such as percentage of turning vehicles, traffic composition, lane width, and approach grade, were examined and modeled. Effects of weather, road surface, light conditions, and speed level were also analyzed. The drop in saturation flow was about 20 to 30 percent under slippery road and snowy conditions. In rainy conditions, the drop was smaller, about 10 percent. The effect of speed on saturation flow is also described. The most important results of this 2-year project are the saturation flow values for different lane types, knowledge of the effect of external factors (especially during winter), and the large database, which can be used for other purposes. The possibility of using special signal control programs under bad road conditions is discussed. With these kinds of programs, better safety and higher capacity can be achieved.
15
Helson, Pascal. "A Mathematical Analysis of Memory Lifetime in a Simple Network Model of Memory". Neural Computation 32, n. 7 (luglio 2020): 1322–54. http://dx.doi.org/10.1162/neco_a_01286.
Abstract (sommario):
We study the learning of an external signal by a neural network and the time to forget it when this network is submitted to noise. The presentation of an external stimulus to the recurrent network of binary neurons may change the state of the synapses. Multiple presentations of a unique signal lead to its learning. Then, during the forgetting time, the presentation of other signals (noise) may also modify the synaptic weights. We construct an estimator of the initial signal using the synaptic currents and in this way define a probability of error. In our model, these synaptic currents evolve as Markov chains. We study the dynamics of these Markov chains and obtain a lower bound on the number of external stimuli that the network can receive before the initial signal is considered forgotten (probability of error above a given threshold). Our results are based on a finite-time analysis rather than large-time asymptotic. We finally present numerical illustrations of our results.
16
Chatterjee, Shre Kumar, Saptarshi Das, Koushik Maharatna, Elisa Masi, Luisa Santopolo, Stefano Mancuso e Andrea Vitaletti. "Exploring strategies for classification of external stimuli using statistical features of the plant electrical response". Journal of The Royal Society Interface 12, n. 104 (marzo 2015): 20141225. http://dx.doi.org/10.1098/rsif.2014.1225.
Abstract (sommario):
Plants sense their environment by producing electrical signals which in essence represent changes in underlying physiological processes. These electrical signals, when monitored, show both stochastic and deterministic dynamics. In this paper, we compute 11 statistical features from the raw non-stationary plant electrical signal time series to classify the stimulus applied (causing the electrical signal). By using different discriminant analysis-based classification techniques, we successfully establish that there is enough information in the raw electrical signal to classify the stimuli. In the process, we also propose two standard features which consistently give good classification results for three types of stimuli—sodium chloride (NaCl), sulfuric acid (H 2 SO 4 ) and ozone (O 3 ). This may facilitate reduction in the complexity involved in computing all the features for online classification of similar external stimuli in future.
17
Rostokin, I. N., E. V. Fedoseeva, E. A. Rostokina e G. G. Shchukin. "Issues of technical implementation of ground-based microwave radiometric system calibration". Journal of Physics: Conference Series 2140, n. 1 (1 dicembre 2021): 012029. http://dx.doi.org/10.1088/1742-6596/2140/1/012029.
Abstract (sommario):
Abstract The theoretical bases of a method of carrying out calibration of microwave radiometric system on a noise signal of the external noise generator are analysed, the parameters setting value of gain of antenna temperature at introduction in structure of system of such external source of a calibration signal are determined. The questions of technical realization of an external source of a calibration signal for microwave radiometric system are considered, the structural scheme is presented, the place of its arrangement in structure of the antenna is determined. The necessity of using a horn antenna to create directional radiation towards the mirror antenna emitter is shown. The data on the design of such a calibration signal source for the case of its use in a three-band microwave radiometric system with the reception of a noise signal at the common antenna aperture and a sequential separation of the input signals of the three bands in the feeder path of the common mirror irradiator are presented. The influence of the design and, accordingly, the directional properties of the horn antenna of a microwave radiometric system calibration signal source on the coefficient characterizing the radiation divergence created by the noise generator horn, as well as the frequency properties of this coefficient are analysed. The results of measurements of radio-thermal radiation by a three-band microwave radiometric system when two calibration periods with reception of a radio-noise signal from an external calibration signal source located at the base of the antenna mirror are presented.
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Bae, Youngseok, Sunghoon Jang, Sungjun Yoo, Minwoo Yi, Joonhyung Ryoo e Jinwoo Shin. "Automatic Bias Control Technique of Dual-Parallel Mach–Zehnder Modulator Based on Simulated Annealing Algorithm for Quadrupled Signal Generation". Photonics 8, n. 3 (17 marzo 2021): 80. http://dx.doi.org/10.3390/photonics8030080.
Abstract (sommario):
The radio frequency (RF) signal generation method using an external modulator is widely used in microwave photonics applications because it has the advantage of being able to generate coherent and stable RF signals with a higher resolution performance compared to the conventional method. A Mach–Zehnder modulator is widely used as an external modulator due to its high electro-optic coefficients and low attenuation characteristics but has a critical problem in that its electrical characteristics are changed by external environments such as temperature. In this paper, we considered the stabilization configuration to overcome this problem and propose an automatic bias control technique based on the simulated annealing algorithm of a dual-parallel Mach–Zehnder modulator (DPMZM) for quadruple signal generation. The proposed technique searches for the bias voltages of the modulator in real-time through the temperature test. In addition, the output of the quadrupled signal of the DPMZM is constantly controlled throughout the temperature range. Finally, it is confirmed that signals of a 10 GHz and 22 GHz frequency are generated using the intermediate frequency signals of a 2.5 GHz and 5.5 GHz frequency with the proposed automatic bias control technique, respectively.
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Huang, Zhongwei, Lifen Cheng e Yang Liu. "Key Feature Extraction Method of Electroencephalogram Signal by Independent Component Analysis for Athlete Selection and Training". Computational Intelligence and Neuroscience 2022 (15 aprile 2022): 1–9. http://dx.doi.org/10.1155/2022/6752067.
Abstract (sommario):
Emotion is an important expression generated by human beings to external stimuli in the process of interaction with the external environment. It affects all aspects of our lives all the time. Accurate identification of human emotional states and further application in artificial intelligence can better improve and assist human life. Therefore, the research on emotion recognition has attracted the attention of many scholars in the field of artificial intelligence in recent years. Brain electrical signal conversion becomes critical, and it needs a brain electrical signal processing method to extract the effective signal to realize the human-computer interaction However, nonstationary nonlinear characteristics of EEG signals bring great challenge in characteristic signal extraction. At present, although there are many feature extraction methods, none of them can reflect the global feature of the signal. The following solutions are used to solve the above problems: (1) this paper proposed an ICA and sample entropy algorithm-based framework for feature extraction of EEG signals, which has not been applied for EEG and (2) simulation signals were used to verify the feasibility of this method, and experiments were carried out on two real-world data sets, to show the advantages of the new algorithm in feature extraction of EEG signals.
20
Yang, Lifeng, Chulin Chen, Zhaojiang Zhang e Xin Wei. "Glucose Determination by a Single 1535 nm Pulsed Photoacoustic Technique: A Multiple Calibration for the External Factors". Journal of Healthcare Engineering 2022 (19 settembre 2022): 1–10. http://dx.doi.org/10.1155/2022/9593843.
Abstract (sommario):
Photoacoustic spectroscopy has been proved to be a potential method for noninvasive blood glucose detection. We used 1535 nm pulsed laser to excite photoacoustic signal in glucose solution and then explored the influence of different glucose concentration on photoacoustic signal to analyze the sensitivity of photoacoustic signal to glucose at this wavelength. We designed a simple photoacoustic cell structure, which used a focused ultrasonic transducer to receive signals, so as to reduce signal attenuation. In terms of the results, we have found that for high-concentration glucose solutions, the results have strong linearity and discrimination, and when the concentration is close to the human body level, the signal difference is not so obvious. Therefore, we explore the external factors affecting the photoacoustic signal in detail and propose a calibration method. Through calibration, the signal generated by the low-concentration glucose solution also has a good linearity.
21
Yamazaki, Tadashi, e Shigeru Tanaka. "Neural Modeling of an Internal Clock". Neural Computation 17, n. 5 (1 maggio 2005): 1032–58. http://dx.doi.org/10.1162/0899766053491850.
Abstract (sommario):
We studied a simple random recurrent inhibitory network. Despite its simplicity, the dynamics was so rich that activity patterns of neurons evolved with time without recurrence due to random recurrent connections among neurons. The sequence of activity patterns was generated by the trigger of an external signal, and the generation was stable against noise. Moreover, the same sequence was reproducible using a strong transient signal, that is, the sequence generation could be reset. Therefore, a time passage from the trigger of an external signal could be represented by the sequence of activity patterns, suggesting that this model could work as an internal clock. The model could generate different sequences of activity patterns by providing different external signals; thus, spatiotemporal information could be represented by this model. Moreover, it was possible to speed up and slow down the sequence generation.
22
Noskov, V. Ya, S. M. Smolskiy, K. A. Ignatkov e A. P. Chupahin. "FEATURES OF AUTODYNE SIGNAL FORMATION WITH EXTERNAL DETECTOR". Telecommunications and Radio Engineering 76, n. 16 (2018): 1463–75. http://dx.doi.org/10.1615/telecomradeng.v76.i16.60.
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Masuda, Naoki, e Kazuyuki Aihara. "Spatiotemporal Spike Encoding of a Continuous External Signal". Neural Computation 14, n. 7 (1 luglio 2002): 1599–628. http://dx.doi.org/10.1162/08997660260028638.
Abstract (sommario):
Interspike intervals of spikes emitted from an integrator neuron model of sensory neurons can encode input information represented as a continuous signal from a deterministic system. If a real brain uses spike timing as a means of information processing, other neurons receiving spatiotemporal spikes from such sensory neurons must also be capable of treating information included in deterministic interspike intervals. In this article, we examine functions of neurons modeling cortical neurons receiving spatiotemporal spikes from many sensory neurons. We show that such neuron models can encode stimulus information passed from the sensory model neurons in the form of interspike intervals. Each sensory neuron connected to the cortical neuron contributes equally to the information collection by the cortical neuron. Although the incident spike train to the cortical neuron is a superimposition of spike trains from many sensory neurons, it need not be decomposed into spike trains according to the input neurons. These results are also preserved for generalizations of sensory neurons such as a small amount of leak, noise, inhomogeneity in firing rates, or biases introduced in the phase distributions.
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Xu, Zihan, Qin Fang, Chengju Liu e Qijun Chen. "Central Pattern Generator with Defined Pulse Signals for Compliant-Resistant Control of Biped Robots". Biomimetics 8, n. 1 (2 marzo 2023): 100. http://dx.doi.org/10.3390/biomimetics8010100.
Abstract (sommario):
For biped robots, the ability to maintain balance under external forces is an essential requirement. Inspired by human beings’ behaviors to resist external forces, a compliant-resistant balance-control method is proposed to keep the biped robot balance subjected to an external force. A model-free trajectory generator is designed based on the central pattern generator (CPG) to generate compliant-resistant human-like behavior. The CPG pattern generator generates the desired pulse signal utilizing Matsuoka’s CPG. The signal modulator applies the defined signal to the robot’s center of mass (CoM) to generate the workspace trajectory when standing on double feet. Moreover, when standing on single foot, the output signal of the CPG will directly act on the hip joint of the robot to generate the joint space trajectory. Furthermore, the motion engine calculates the workspace trajectory into joint sequence values. The proposed control strategy can generate defined pulse signals to realize compliant-resistant balance control for biped robots. The control strategy proposed in this paper is verified in the NAO simulation environment.
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WAH WU, CHAI, GUO-QUN ZHONG e LEON O. CHUA. "SYNCHRONIZING NONAUTONOMOUS CHAOTIC SYSTEMS WITHOUT PHASE-LOCKING". Journal of Circuits, Systems and Computers 06, n. 03 (giugno 1996): 227–41. http://dx.doi.org/10.1142/s0218126696000182.
Abstract (sommario):
Pecora and Carroll1 have shown how two nonautonomous chaotic circuits driven by periodic forcing can be synchronized using the master-slave driving principle. However, in their scheme, the periodic forcing in both circuits needs to be phase-locked through some additional circuitry for the system to synchronize. In this paper, we show two ways in which this can be avoided. In the first scheme, the two circuits are connected in a master-slave driving configuration and the periodic forcing is included in the driving signal such that it eliminates the need for the slave circuit to have an external periodic forcing signal. In addition, we can recover the periodic forcing signal at the slave circuit. In the second scheme, the two circuits are connected in a mutual coupling configuration. The two circuits will synchronize regardless of what the periodic forcing signals of the two circuits are. In particular, the two periodic forcing signals could have different phases, different frequencies, or different shapes. We discuss two interpretations of these synchronization schemes. First, we consider them as communication systems when the periodic forcing signal is replaced by a properly encoded information signal. We illustrate this in a physical circuit implementation. Second, we consider them as synchronization schemes for nonidentical systems by considering the external forcing signal as an error signal due to the difference between the two systems.
26
Wang, Haifei, Junqing Yin, Cheng Xin, Chan Li e Yongdang Chen. "Research on Magnetic Field-Based Damage Detection Technology for Ferromagnetic Microwires". Sensors 24, n. 3 (29 gennaio 2024): 878. http://dx.doi.org/10.3390/s24030878.
Abstract (sommario):
Composite materials are frequently exposed to external factors during their operational service, resulting in internal structural damage which subsequently impacts their structural performance. This paper employs ferromagnetic materials for their sensitivity to magnetic field strength. By detecting variations in the magnetic field within the embedded ferromagnetic microwires of composite materials, the aim is to indirectly assess the health status of the composite materials. Firstly, a theoretical numerical model for magnetic field intensity at the crack site was established. Subsequently, a finite element model was employed to analyze the variations in the magnetic characteristics of ferromagnetic microwires at the crack site. Under different parameter conditions, the patterns of magnetic signals at the crack site were determined. The results indicate that with an increase in the angle between the external magnetic field and the crack, the fitted curve of the magnetic signal shows a linear increase. The distance between the peak and valley of the radial magnetic signal in the axial direction decreases, and the axial magnetic signal transitions from double-peak to single-peak. With the increase in crack depth, the fitted curve of the magnetic signal shows a linear increase, and the magnetic signal at the crack tip also exhibits a linear increase. An increase in crack width leads to a non-linear decrease in the fitted curve of the magnetic signal, and after reaching a certain width, the magnetic signal stabilizes. For two identical cracks at different distances, the magnetic signal exhibits a transition from a complete pattern to two complete patterns. With the increase in the external magnetic field, the magnetic signal shows a completely regular linear increase. By analyzing and calculating the variations in magnetic signals, the patterns of magnetic characteristics under the damaged state of ferromagnetic microwires were obtained. This serves as a basis for assessing whether they can continue in service and for evaluating the overall health status of composite materials.
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Даянова, D. Dayanova, Вохмина, Yu Vokhmina, Гавриленко, T. Gavrilenko, Игуменов e D. Igumenov. "Stochastic estimation of chaotic dynamics models of the biological systems". Journal of New Medical Technologies. eJournal 8, n. 1 (5 novembre 2014): 1–6. http://dx.doi.org/10.12737/3861.
Abstract (sommario):
Process modeling is one of the main directions in science and engineering. When there is a model of simple system it is possible to obtain the parameters of its state vector before a process starts. However, the modeling of complex processes (systems) applying standard methods of computing and simulation software is confronted with difficulties of chaotic dynamics of such systems. A number of models that allow to describing the dynamics of complex biological dynamic systems is extremely small, as to repeat the same results of experiments it is impossible on the basis of deterministic or stochastic models. In additional, the authors propose a model for description of human state vector through three-compartment two-cluster control system. This model may be implemented using an application package exhibiting an operation of each cluster separately. The output signals of the model seen can be compared with the actual experimental data observed as output signals. The signals obtained at the output of the simulation model show different states of the system under external control actions which cause the change in the internal properties and states due to external (disturbance) signal. Control external signal from the first cluster and accordingly the output signal from the second cluster were divided into four main components that had the same analogues in the dynamics of complex biological behavior of dynamical systems [2,4].
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Huang, Xu, Huibin Xu, Wuming He, Mengjia Zeng e Mengfei Wu. "Intelligent Light Emitting Diode Flashing Supplementary Lighting Control Design and Its Big Data Illumination Analysis". Journal of Nanoelectronics and Optoelectronics 19, n. 6 (1 giugno 2024): 613–20. http://dx.doi.org/10.1166/jno.2024.3611.
Abstract (sommario):
Considering the inherent advantages of the Light Emitting Diode (LED) in the field of illumination, this work designs an intelligent supplementary lighting system using LED as the light source. Combining microcontroller and electronic circuit theory, the circuit is built with the microcontroller PIC16F873 as the core control chip. The system utilizes an external 220 V AC-20 V DC conversion power supply, hence operating on a 20 V DC power source. The system consists of four hardware parts: the onboard power supply uses TI-produced TPS54331 as the control chip to achieve voltage conversion; the external signals (flashing and burst flashing signals) are isolated from the microcontroller through an optocoupler circuit; the PWM pulses output from the microcontroller’s RC1/CCP2 pins drive the corresponding switching tubes to achieve the flashing function; the flashing synchronization signal is output externally after optocoupler isolation, and its synchronous output with the flashing signal is achieved through an optocoupler after LED conduction; the circuit is established using TI-produced differential bus transceiver SN65LBC184D to convert the external 485 differential signal to the level signal required by the microcontroller. In the experiment, after completing the hardware design, connecting the LED panel, and debugging the test program, it is found that the designed lighting system has a good supplementary lighting effect. According to the PWM output waveform, the flashing effect meets the design expectations. The Hadoop big data computing platform is introduced. Simulation testing reveals that under no backlight conditions, the system achieves an illumination intensity of around 20 klx at a distance of about 10 meters. With backlight conditions, the system maintains an illumination intensity of around 1.5 klx at a distance of about 10 meters. Further calculations are performed to analyze the variation in foot traffic within the test area’s illumination over 24 hours. The total illumination intensity during different time intervals is compiled, confirming that the system can autonomously adjust the illumination intensity of the area based on changes in foot traffic.
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Zhang, Xuping, Yunyin Zheng, Chi Zhang, Qiuhao Dong, Shisong Zhao, Jingxiao Liu, Feng Wang, Yixin Zhang e Fei Xiong. "A Fading Tolerant Phase-Sensitive Optical Time Domain Reflectometry Based on Phasing-Locking Structure". Electronics 10, n. 5 (25 febbraio 2021): 535. http://dx.doi.org/10.3390/electronics10050535.
Abstract (sommario):
The demand for phase-sensitive optical time domain reflectometry (φ-OTDR), which is capable of reconstructing external disturbance accurately, is increasing. However, φ-OTDR suffers from fading where Rayleigh backscattering traces (RBS) have low amplitude and may be lower than the noise floor. Therefore, signal-to-noise ratio (SNR) is reduced. In conventional coherent φ-OTDR, an acoustic optical modulator (AOM), which consists of an RF driving source and an acousto-optic crystal, is commonly used to generate optical pulses and frequency shifts. Since RF driving and external modulation signals come from an independent oscillation source, every intermediate frequency (IF) trace has a different phase bias. Therefore, it is difficult to average the IF signals directly for noise reduction. In this paper, a coherent φ-OTDR system based on phase-locking structure was proposed. This structure provided a clock homologous carrier signal, a modulation signal and a data acquisition (DAQ) trigger signal. Then, moving average methods were taken on IF signals before phase demodulating to reduce the overall noise floor of the system. This new φ-OTDR is more tolerant to fading, which can provide higher accuracy for vibration reconstruction. The frequency response range of vibration was as low as 1Hz, and a 25dB improvement of SNR was achieved.
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Marvel, Kate, Mark Zelinka, Stephen A. Klein, Céline Bonfils, Peter Caldwell, Charles Doutriaux, Benjamin D. Santer e Karl E. Taylor. "External Influences on Modeled and Observed Cloud Trends". Journal of Climate 28, n. 12 (11 giugno 2015): 4820–40. http://dx.doi.org/10.1175/jcli-d-14-00734.1.
Abstract (sommario):
Abstract Understanding the cloud response to external forcing is a major challenge for climate science. This crucial goal is complicated by intermodel differences in simulating present and future cloud cover and by observational uncertainty. This is the first formal detection and attribution study of cloud changes over the satellite era. Presented herein are CMIP5 model-derived fingerprints of externally forced changes to three cloud properties: the latitudes at which the zonally averaged total cloud fraction (CLT) is maximized or minimized, the zonal average CLT at these latitudes, and the height of high clouds at these latitudes. By considering simultaneous changes in all three properties, the authors define a coherent multivariate fingerprint of cloud response to external forcing and use models from phase 5 of CMIP (CMIP5) to calculate the average time to detect these changes. It is found that given perfect satellite cloud observations beginning in 1983, the models indicate that a detectable multivariate signal should have already emerged. A search is then made for signals of external forcing in two observational datasets: ISCCP and PATMOS-x. The datasets are both found to show a poleward migration of the zonal CLT pattern that is incompatible with forced CMIP5 models. Nevertheless, a detectable multivariate signal is predicted by models over the PATMOS-x time period and is indeed present in the dataset. Despite persistent observational uncertainties, these results present a strong case for continued efforts to improve these existing satellite observations, in addition to planning for new missions.
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Kitamura, Aya, Takeo Minematsu, Gojiro Nakagami, Tomomitsu Miyagaki, Sanae Sasaki, Chieko Hayashi e Hiromi Sanada. "Assessing subclinical inflammation by peroxidase detection in patients with pressure ulcers". Journal of Wound Care 28, n. 9 (2 settembre 2019): 586–91. http://dx.doi.org/10.12968/jowc.2019.28.9.586.
Abstract (sommario):
Objective: This study aimed to examine the superiority of peroxidase detection of macroscopic observations using rat wounds, and to test the external validity of the peroxidase analysis in pressure ulcers (PU) in humans. Method: In the animal study, rat wounds were analysed. A cross-sectional study analysed, by wound blotting, exudate samples from full-thickness PUs. Peroxidase activity was divided into two groups (ring and non-ring signals). Scores in the ‘inflammation/infection’ and ‘necrotic tissue’ components of DESIGN, a classification tool of PUs, were compared between the groups. Results: In the animal study, 20 rat wounds were assessed and in the clinical study, 62 samples were collected from 26 full-thickness PUs of 21 patients aged ≥ 65 years. In the animal study, five of six wounds with clinical inflammation signs showed ring signal (defined as a signal on the wound edge and no signal on the wound bed). While the tissue sections of three wounds with a ring signal showed inflammatory features, they showed no clinical signs of ‘inflammation/infection’. In the clinical study, which analysed 630 ring and 32 non-ring signals, 13 samples in the ring signal group and five in the non-ring signal group had ‘inflammation/infection; scores of ≥1 (p=0.016). Despite having no clinical signs, 17 samples showed the ring signal. Conclusion: This study revealed the external validity of the wound blotting analysis of peroxidase and demonstrated its use to detect subclinical inflammation.
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Бакунин, В. Л., Ю. А. Гузнов, Г. Г. Денисов, Н. И. Зайцев, С. А. Запевалов, А. Н. Куфтин, Ю. В. Новожилова, А. П. Фокин, А. В. Чирков e А. С. Шевченко. "Экспериментальное исследование влияния внешнего сигнала на режим генерации гиротрона мегаваттного уровня мощности". Письма в журнал технической физики 44, n. 11 (2018): 38. http://dx.doi.org/10.21883/pjtf.2018.11.46195.17109.
Abstract (sommario):
AbstractThe frequency capture of radiation by an external signal was experimentally studied for the first time for a megawatt-power gyrotron. An external signal from the magnetron at a frequency of 35 GHz entered the working space of the gyrotron through a synthesized two-mirror quasi-optical converter that allowed transforming the input signal into a working mode. This converter has been recently developed and implemented in the Institute of Applied Physics, Russian Academy of Sciences. The radiation spectra were experimentally obtained in modes of frequency capture and frequency beats. The dependence of the frequency capture bandwidth on the power of the external signal was found. Comparison of experimental results with the data of numerical modelling of gyrotron equations with an external signal showed their good agreement.
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Dubinov, A. E., e V. D. Selemir. "Vircator generation spectrum controlled by an external SHF signal". Technical Physics Letters 26, n. 7 (luglio 2000): 547–49. http://dx.doi.org/10.1134/1.1262907.
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Barthauer, Mirko, e Bernhard Friedrich. "Connecting microscopic traffic simulation and LISA+ external signal control". Transportation Research Procedia 27 (2017): 420–27. http://dx.doi.org/10.1016/j.trpro.2017.12.007.
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Dresp, Birgitta. "External regularities and adaptive signal exchanges in the brain". Behavioral and Brain Sciences 24, n. 4 (agosto 2001): 663–64. http://dx.doi.org/10.1017/s0140525x01310087.
Abstract (sommario):
Shepard's concept of internalization does not suggest mechanisms which help to understand how the brain adapts to changes, how representations of a steadily changing environment are updated or, in short, how brain learning continues throughout life. Neural mechanisms, as suggested by Barlow, may prove a more powerful alternative. Brain theories such as Adaptive Resonance Theory (ART) propose mechanisms to explain how representational activities may be linked in space and time. Some predictions of ART are confirmed by psychophysical and neurophysiological data. [Barlow; Shepard]
36
Dzhotyan, G. P., e A. V. Mesropyan. "Singly resonant optical parametric oscillator with external signal injection". Soviet Journal of Quantum Electronics 20, n. 12 (31 dicembre 1990): 1450–52. http://dx.doi.org/10.1070/qe1990v020n12abeh007590.
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Wang, Yantong, e Lingyi Zhou. "Innovative Analysis and Application on Magnetograms Signal". Journal of Physics: Conference Series 2174, n. 1 (1 gennaio 2022): 012087. http://dx.doi.org/10.1088/1742-6596/2174/1/012087.
Abstract (sommario):
Abstract This study aims to make research on magnetocardiography (magnetograms) signals. Magnetocardiogram is a non-invasive method to record and analyze the magnetic components of the electromagnetic field generated by cardiac electrical activity in the cardiac cycle. We conclude the basic characteristics of the magnetograms signal to summarize the existing magnetograms measurement principles. Then we combine the initial development process and detection means of magnetograms by discussing the signal shielding of magnetograms from two aspects of hardware and software. We compare several methods of shielding electromagnetic signals on hardware and finally obtain an excellent means to shield external signals at this stage. We also conclude the current application of magnetograms in medical treatment.
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Leong, D. A. "A complex mechanism of facilitation in pituitary ACTH cells: recent single-cell studies". Journal of Experimental Biology 139, n. 1 (1 settembre 1988): 151–68. http://dx.doi.org/10.1242/jeb.139.1.151.
Abstract (sommario):
The transfer of information by chemical signals during complex biological processes can, with increasing frequency, be described in terms of interacting signal pairs. External signalling is rarely monolithic; rather, signal pairs are utilized in processes such as hormone secretion, neurotransmission, cell growth and differentiation. The dualism of external signalling often results in the occurrence of synergy. One signal appears to turn the cell on or off, and its synergistic partner increases cell responsiveness, providing gain control of the cellular response. ACTH release provoked by certain stressors arises from a synergistic interaction between two hypothalamic hormones: corticotropin releasing hormone (CRH) and a modulator such as vasopressin (AVP). The pituitary ACTH cell has been used to unravel the intracellular messenger equivalents of an external signal interaction that generates synergy. Research emphasizes the single cell approach. Direct measurements of intracellular free Ca2+ were performed using the Ca2+-sensitive fluorescent probe fura-2/AM and instrumentation for digital image processing. A reverse haemolytic plaque assay was used to measure cumulative ACTH release from single pituitary cells in culture. What is the physiological role of intracellular Ca2+ as a messenger? What are the feedforward and feedback relationships between major second messengers [cyclic AMP, diacylglycerol (DAG), inositol 1,4,5-trisphosphate (Ins(1,4,5)P3)] and intracellular Ca2+? That is, how are individual messenger circuits “wired' within ACTH cells. Intracellular Ca2+ may act as a common signal into which interacting second messenger signals [cyclic AMP, Ins(1,4,5)P3, DAG] are transduced and integrated to govern ACTH release. A novel circuit of messenger pathways linked by Ca2+ is proposed as the intracellular basis for the synergistic interaction of CRH- and AVP-regulated ACTH release.
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Scally, Karen, Judith L. Charlton, Robert Iansek, John L. Bradshaw, Simon Moss e Nellie Georgiou-Karistianis. "Impact of External Cue Validity on Driving Performance in Parkinson's Disease". Parkinson's Disease 2011 (2011): 1–10. http://dx.doi.org/10.4061/2011/159621.
Abstract (sommario):
This study sought to investigate the impact of external cue validity on simulated driving performance in 19 Parkinson's disease (PD) patients and 19 healthy age-matched controls. Braking points and distance between deceleration point and braking point were analysed for red traffic signals preceded either by Valid Cues (correctly predicting signal), Invalid Cues (incorrectly predicting signal), and No Cues. Results showed that PD drivers braked significantly later and travelled significantly further between deceleration and braking points compared with controls for Invalid and No-Cue conditions. No significant group differences were observed for driving performance in response to Valid Cues. The benefit of Valid Cues relative to Invalid Cues and No Cues was significantly greater for PD drivers compared with controls. Trail Making Test (B-A) scores correlated with driving performance for PDs only. These results highlight the importance of external cues and higher cognitive functioning for driving performance in mild to moderate PD.
40
Wang, Ling Ling, Hong Xia Luo, Jian Hua Cao, Kun Lu, Ji Hua Fang e Shuai Chen. "The Test and Time-Frequency Domain Analysis on Plant Electrical Signal Based on Virtual Instrument". Applied Mechanics and Materials 738-739 (marzo 2015): 686–89. http://dx.doi.org/10.4028/www.scientific.net/amm.738-739.686.
Abstract (sommario):
We tried to obtain numbers of the plant electrical signal with the help of experiments. We made comprehensive treatment and analysis by using the time domain analysis method and frequency domain analysis method to the large numbers of data of the plant electrical signal. The experiment finds that that the plant electrical signal is a kind of low frequency,tiny and fairly stable signal. The features of plant electrical signals remarkably responsive to external stimuli. The measuring precision is limited in the test, so the conclusion only can be mined and used for for future research.
41
Guo, Hang, Ji Wan, Haobin Wang, Hanxiang Wu, Chen Xu, Liming Miao, Mengdi Han e Haixia Zhang. "Self-Powered Intelligent Human-Machine Interaction for Handwriting Recognition". Research 2021 (1 aprile 2021): 1–9. http://dx.doi.org/10.34133/2021/4689869.
Abstract (sommario):
Handwritten signatures widely exist in our daily lives. The main challenge of signal recognition on handwriting is in the development of approaches to obtain information effectively. External mechanical signals can be easily detected by triboelectric nanogenerators which can provide immediate opportunities for building new types of active sensors capable of recording handwritten signals. In this work, we report an intelligent human-machine interaction interface based on a triboelectric nanogenerator. Using the horizontal-vertical symmetrical electrode array, the handwritten triboelectric signal can be recorded without external energy supply. Combined with supervised machine learning methods, it can successfully recognize handwritten English letters, Chinese characters, and Arabic numerals. The principal component analysis algorithm preprocesses the triboelectric signal data to reduce the complexity of the neural network in the machine learning process. Further, it can realize the anticounterfeiting recognition of writing habits by controlling the samples input to the neural network. The results show that the intelligent human-computer interaction interface has broad application prospects in signature security and human-computer interaction.
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STELMASIAK, Zdzisław, e Mariusz RUDNICKI. "Impact of external interferences on vibroacoustic signals coming from combustion engine during cold test". Combustion Engines 160, n. 1 (1 febbraio 2015): 26–35. http://dx.doi.org/10.19206/ce-116899.
Abstract (sommario):
In the paper is presented impact of external interferences on vibroacoustic signals coming from a spark ignition engine’s vibrations in cold test performed on engine assembly line. As the basis to the analysis were used signals of piezoelectric sensor mounted on cylinder block of the engine driven by electric motor. In course of the testing it has been used the order tracking analysis of the vibrations during the cold test, while experimental results were used to statistic analysis of significance of influence with use of the MiniTab computer program. The main objective of the investigations was to verify actually obtained vibroacoustic signals and to minimize interferences coming from the measuring system. It should contribute to reduction of tolerance limits and improved detection of faulty engines with use of vibroacoustic methods. The investigations have shown significant impact of contact surface of the cylinder block with the sensor and impact of deformations of compression spring on results of recorded vibroacoustic signal. Such impact should be taken into considerations in numerical analysis of the signal. It has been proposed to perform activities to reduce influence of the interferences on recorded signals. Results of the investigations have been already utilized in production cold tests of spark ignition engines.
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Zhang, Mei Jun, Chuang Wang, Qin Cao e Hao Chen. "Improved EEMD on the Application Research of Signal Trend Analysis". Advanced Materials Research 591-593 (novembre 2012): 2020–23. http://dx.doi.org/10.4028/www.scientific.net/amr.591-593.2020.
Abstract (sommario):
The trend of the measured signal can not only reflect the influence of the external environment, and also reflect the performance of the machine itself mutations. Therefore, removing and extracting tendency item is the necessary link in signal pretreatment.In order to eliminate endpoint effect and modal aliasing phenomenon in EMD and EEMD, based on EEMD,improved EEMD is put forward and the improved EEMD in the application of the signal trend analysis is researched in this paper.In the measured signals to join in a ramp signals,With the improved EEMD decomposition extracted residual items,and the residual items with the original slope signal similarity analysis,the similarity is 0.975.compared to EMD extracted residual items similarity 0.898, EEMD extracted residual items similarity 0.961,the improved EEMD extracted residual item can more accurately reflect the trend of signal.
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Hadwiger, Jeffrey A., e Hoai-Nghia Nguyen. "MAPKs in development: insights from Dictyostelium signaling pathways". BioMolecular Concepts 2, n. 1-2 (1 aprile 2011): 39–46. http://dx.doi.org/10.1515/bmc.2011.004.
Abstract (sommario):
AbstractMitogen activated protein kinases (MAPKs) play important roles in the development of eukaryotic organisms through the regulation of signal transduction pathways stimulated by external signals. MAPK signaling pathways have been associated with the regulation of cell growth, differentiation, and chemotaxis, indicating that MAPKs contribute to a diverse set of developmental processes. In most eukaryotes, the diversity of external signals is likely to far exceed the diversity of MAPKs, suggesting that multiple signaling pathways might share MAPKs. Do different signaling pathways converge before MAPK function or can MAPKs maintain signaling specificity through interactions with specific proteins? The genetic and biochemical analysis of MAPK pathways in simple eukaryotes such as Dictyostelium offers opportunities to investigate functional specificity of MAPKs in G-protein-mediated signal transduction pathways. This review considers the regulation and specificity of MAPK function in pathways that control Dictyostelium growth and development.
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Han, Xian Qin, e Xiang Lei Zhu. "Multi-Signal Generator Design". Advanced Materials Research 542-543 (giugno 2012): 584–90. http://dx.doi.org/10.4028/www.scientific.net/amr.542-543.584.
Abstract (sommario):
Signal generator is electronic equipment which can produce standard signals, and it often is used in industrial production electronic laboratories and the electronic equipment. Signal generator can achieve in a variety of methods, and the higher frequency and the more waveform is the better the signal generator condition. We can consider its implementation from the production and using areas. This paper will use function in the external circuit chip ICL8038 and electronic way to produce triangle wave, sine wave, rectangular wave,which are three basic rectangular waveforms, then the wave through ICM7216D, crystal, capacitors, switches and LED digital which are composed of the circuit to show the frequency and makes the sine wave produce a frequency modulation wave through FM circuit.
46
SARMA, B. K., A. BURAGOHAIN e JOYANTI CHUTIA. "PERIODIC WINDOW AND PERIOD SUBTRACTING IN AN ION-BEAM PLASMA SYSTEM". International Journal of Bifurcation and Chaos 03, n. 02 (aprile 1993): 455–58. http://dx.doi.org/10.1142/s0218127493000350.
Abstract (sommario):
Observation of different sequences of bifurcations in an ion-beam plasma system excited by an external sinusoidal signal is reported. Under the influence of an external periodic oscillation applied to the anode of the source chamber of a double plasma device, periodic windows are observed with the variation of theamplitude of the external signal when the frequency of the applied signal is at the edge of the total suppressed position of the internal oscillation. On the other hand, period subtracting phenomena are observed with the variation of the amplitude of the applied signal, when the frequency of the applied signal is lowered but fixed within the suppression range of the internal oscillation and with low modulation depth.
47
Lu, Zhong-Lin, Xiangrui Li, Bosco S. Tjan, Barbara A. Dosher e Wilson Chu. "Attention Extracts Signal in External Noise: A BOLD fMRI Study". Journal of Cognitive Neuroscience 23, n. 5 (maggio 2011): 1148–59. http://dx.doi.org/10.1162/jocn.2010.21511.
Abstract (sommario):
On the basis of results from behavioral studies that spatial attention improves the exclusion of external noise in the target region, we predicted that attending to a spatial region would reduce the impact of external noise on the BOLD response in corresponding cortical areas, seen as reduced BOLD responses in conditions with large amounts of external noise but relatively low signal, and increased dynamic range of the BOLD response to variations in signal contrast. We found that, in the presence of external noise, covert attention reduced the trial-by-trial BOLD response by 15.5–18.9% in low signal contrast conditions in V1. It also increased the BOLD dynamic range in V1, V2, V3, V3A/B, and V4 by a factor of at least three. Overall, covert attention reduced the impact of external noise by about 73–85% in these early visual areas. It also increased the contrast gain by a factor of 2.6–3.8.
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Cui, H., e G. Zhang. "HIGH-RESOLUTION OPTICAL SATELLITE IMAGES COLOR CONSISTENCY METHOD BASED ON EXTERNAL COLOR REFERENCES". ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences V-3-2020 (3 agosto 2020): 663–68. http://dx.doi.org/10.5194/isprs-annals-v-3-2020-663-2020.
Abstract (sommario):
Abstract. Affected by factors such as season, illumination, atmospheric and sensor distortion, different satellite images often show obvious color difference, resulting in “stitching seams” at the edge of adjacent images, which seriously affects the application of satellite images. This study proposes a novel color consistency method for optical satellite images utilizing external color reference. Firstly, we improved the dark channel defogging method combining with the atmospheric distribution characteristics of satellite images, and used it to perform atmospheric correction on satellite images; Secondly, we corrected the color of atmospheric corrected satellite images through low-frequency signal replacement. Finally, we use a linear model to establish the relationship between high and low frequency signals, and stretching the high-frequency signal of images through local modelling. We selected two sets of representative experimental data for experiments, both the visual and quantitative obtained excellent results.
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Yu, Yuan, Quan Bo Yuan e Xu Li. "Design and Research of Biological Information Based on the Signal Extraction Algorithm". Applied Mechanics and Materials 599-601 (agosto 2014): 1297–300. http://dx.doi.org/10.4028/www.scientific.net/amm.599-601.1297.
Abstract (sommario):
This article will extracte biological EEG information, extracted by EEG brain-computer interaction module. It has taken advantage of brain-computer interaction techniques, accurately extracted EEG data, modeling the data, analyzed EEG law, and the signal is used in Bluetooth smart car.The human brain with computers and external communications equipment that can detect and record brain activity by brain-computer interaction technology and brain signals. Brain waves are turned into a language that the computer can understand, so as to effectively control the vehicle, or other external devices.
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Li, Yang, e Zhiguo Tang. "Research on the Propagation Characteristics of High Frequency Partial Discharge Signal in Transformer". Journal of Physics: Conference Series 2290, n. 1 (1 giugno 2022): 012066. http://dx.doi.org/10.1088/1742-6596/2290/1/012066.
Abstract (sommario):
Abstract In order to study the information contained in the high frequency partial discharge and the influence of transformer winding on the propagation of partial discharge signal, this paper injects high frequency small signals into the external leads, internal winding and enclosing screen of 110kV three-phase double-winding transformer to simulate the external discharge, inside and outside of the winding discharge to study the propagation characteristics of transformer partial discharge signal. The study shows that the partial discharge signal is coupled from one to others, and the signal can be detected at each detection end when partial discharge occurs; the partial discharge signal consists of high-frequency component and low-frequency component, the high-frequency component is mainly propagated through the capacitance between the windings, and the low-frequency component is mainly propagated through the windings; The polarity of the first wave of the time domain signal is different when the discharge of the internal winding of the transformer propagates to each detection point, the polarity of the first wave of the time domain signal is the same when the discharge of the outside winding propagates to each detection point. Among them, the discharge of the outside winding mainly propagates through the capacitor, and the low-frequency components of each detection terminal are seriously attenuated.