Detection Of Rate Changes Research Articles

A method to improve the accuracy of SAR image change detection by using an image enhancement method

Accuracy in remote sensing image change detection is an important area of study. A new approach for improving the change detection accuracy of SAR remote sensing images is investigated in this paper. The research in this paper is presented in three parts. First, we proposed a new image enhancement algorithm. We combined the image enhancement algorithm based on the combination of the wavelet domain and spatial domain and the power-law. The contrast of the original image was enhanced by histogram equalization; then, the high- and low-frequency coefficients of the image were processed by wavelet fusion, and the image was sharpened by a nonsharpening mask so that the image could be sharpened from the image. Compared with other correlation enhancement contrast algorithms, we assert that the algorithm retains the high-frequency details of the image while improving its sharpness. Second, we propose a new change detection algorithm. A power rate change detection algorithm is used to improve image brightness, a logarithmic difference map is used to obtain a difference map, and an FLCM clustering algorithm is used to improve the clustering effect by suppressing noise from domain information. To improve detection accuracy, a saliency map is extracted from the difference map, the former of which is then used. The detection template obtained from the graph greatly reduces the range of change detection and effectively reduces the noise of the SAR image. The proposed power rate change detection algorithm is superior to similar algorithms. Third, our proposed enhancement algorithm is applied to our proposed change detection algorithm, which further improves the accuracy of image change detection.

Multi-scale detection of rate changes in spike trains with weak dependencies

The statistical analysis of neuronal spike trains by models of point processes often relies on the assumption of constant process parameters. However, it is a well-known problem that the parameters of empirical spike trains can be highly variable, such as for example the firing rate. In order to test the null hypothesis of a constant rate and to estimate the change points, a Multiple Filter Test (MFT) and a corresponding algorithm (MFA) have been proposed that can be applied under the assumption of independent inter spike intervals (ISIs). As empirical spike trains often show weak dependencies in the correlation structure of ISIs, we extend the MFT here to point processes associated with short range dependencies. By specifically estimating serial dependencies in the test statistic, we show that the new MFT can be applied to a variety of empirical firing patterns, including positive and negative serial correlations as well as tonic and bursty firing. The new MFT is applied to a data set of empirical spike trains with serial correlations, and simulations show improved performance against methods that assume independence. In case of positive correlations, our new MFT is necessary to reduce the number of false positives, which can be highly enhanced when falsely assuming independence. For the frequent case of negative correlations, the new MFT shows an improved detection probability of change points and thus, also a higher potential of signal extraction from noisy spike trains.

A multiple filter test for the detection of rate changes in renewal processes with varying variance

Nonstationarity of the event rate is a persistent problem in modeling time series of events, such as neuronal spike trains. Motivated by a variety of patterns in neurophysiological spike train recordings, we define a general class of renewal processes. This class is used to test the null hypothesis of stationary rate versus a wide alternative of renewal processes with finitely many rate changes (change points). Our test extends ideas from the filtered derivative approach by using multiple moving windows simultaneously. To adjust the rejection threshold of the test, we use a Gaussian process, which emerges as the limit of the filtered derivative process. We also develop a multiple filter algorithm, which can be used when the null hypothesis is rejected in order to estimate the number and location of change points. We analyze the benefits of multiple filtering and its increased detection probability as compared to a single window approach. Application to spike trains recorded from dopamine midbrain neurons in anesthetized mice illustrates the relevance of the proposed techniques as preprocessing steps for methods that assume rate stationarity. In over 70% of all analyzed spike trains classified as rate nonstationary, different change points were detected by different window sizes.

Rate change detection of frequency modulated signals: developmental trends

The aim of this study was to examine developmental trends in rate change detection of auditory rhythmic signals (repetitive sinusoidally frequency modulated tones). Two groups of children (9-10 years old and 11-12 years old) and one group of young adults performed a rate change detection (RCD) task using three types of stimuli. The rate of stimulus modulation was either constant (CR), raised by 1 Hz in the middle of the stimulus (RR1) or raised by 2 Hz in the middle of the stimulus (RR2). Performance on the RCD task significantly improved with age. Also, the different stimuli showed different developmental trajectories. When the RR2 stimulus was used, results showed adult-like performance by the age of 10 years but when the RR1 stimulus was used performance continued to improve beyond 12 years of age. Rate change detection of repetitive sinusoidally frequency modulated tones show protracted development beyond the age of 12 years. Given evidence for abnormal processing of auditory rhythmic signals in neurodevelopmental conditions, such as dyslexia, the present methodology might help delineate the nature of these conditions.

Relationship Between Central Auditory Processing and Reading Skills: Preliminary Observations in Hebrew Speaking Children

To assess the relationships between central auditory processing (CAP) of sinusoidally modulated speech-like and non-speech acoustic signals and reading skills in shallow (pointed) and deep (unpointed) Hebrew orthographies. Twenty unselected fifth-grade Hebrew speakers performed a rate change detection (RCD) task using the aforementioned acoustic signals. They also performed reading and general ability (IQ) tests. After controlling for general ability, RCD tasks contributed a significant unique variance to the decoding skills. In addition, there was a fairly strong correlation between the score on the RCD with the speech-like stimuli and the unpointed text reading score. CAP abilities may affect reading skills, depending on the nature of orthography (deep vs shallow), at least in the Hebrew language.

Does Experimental Pain Affect Auditory Processing of Speech-relevant Signals? A Study in Healthy Young Adults

To assess the effect of tonic pain stimulation on auditory processing of speech-relevant acoustic signals in healthy pain-free volunteers. Sixty university students, randomly assigned to either a thermal pain stimulation (46 degrees C/6 min) group (PS) or no pain stimulation group (NPS), performed a rate change detection task (RCDT) involving sinusoidally frequency-modulated vowel-like signals. Task difficulty was manipulated by changing the rate of the modulated signals (henceforth rate). Perceived pain intensity was evaluated using a visual analog scale (VAS) (0-100). Mean pain rating was approximately 33 in the PS group and approximately 3 in the NPS group. Pain stimulation was associated with poorer performance on the RCDT, but this trend was not statistically significant. Performance worsened with increasing rate of signal modulation in both groups (p < 0.0001), with no pain by rate interaction. The present findings indicate a trend whereby mild or moderate pain appears to affect auditory processing of speech-relevant acoustic signals. This trend, however, was not statistically significant. It is possible that more intense pain would yield more pronounced (deleterious) effects on auditory processing, but this needs to be verified empirically.

The effects of noxious heat, auditory stimulation, a cognitive task, and time on task on pain perception and performance accuracy in healthy volunteers: A new experimental model

The effects of cognitive and competing sensory processing tasks on pain perception and as a function of time are only partially understood. To study these effects, we compared the simultaneous effects of noxious heat stimulation (HS), auditory stimulation (AS) (sinusoidally modulated speech-like signal, SMSLS), and a cognitive task (CT) (rate change detection of the SMSLS) on pain perception and task performance over repeated experimental runs. Sixty healthy paid volunteers were randomly assigned to four groups, one exposed to AS while performing the CT, one to HS (46 °C/6 min), one to AS and HS, and one to AS and HS while performing the CT. Each group performed the experimental run four times, each run for 6 min. Immediately after each run, the subjects rated pain intensity using a VAS (0–100). Two-way RM-ANOVA for analyzing pain intensities among the three heat pain groups demonstrated significant differences of VAS ratings ( F 2,179=4.57, P=0.019), being highest in the HS group (55±0.7SEM), followed by the AS+HS (39±6.8) and AS+HS+CT (33±0.7) groups. Post-hoc analyses revealed that group HS differed significantly from group AS+HS+CT and from group AS+HS ( P<0.05, SNK), whereas group AS+HS did not differ significantly from group AS+HS+CT. Neither pain rating, nor rate of errors on the CT varied significantly across runs. These findings point to a significant influence of competing passive sensory processing on pain perception, with the cognitive task not necessarily adding to the perception of pain. Advantages and shortcomings of the present experimental model for future pain studies are discussed.

Failure Detection by Means of Singular Systems

This paper deals with the abrupt changes detection in the linear dynamical SISO systems. Our method is based on the singular state modeling which takes into account the parameter jumps in the model. The estimation is then achieved by an extended Kalman filter specifically developed for this class of models. Finally the designed detector is applied to the engine rate change detection of a water-steam engine.

Timely monthly surveillance of birth prevalence rates of congenital malformations and genetic disorders ascertained by registries or other systematic data bases

In many jurisdictions large data sets on malformations are now collected routinely in order to define prevalence rates of malformations in infants and children, to detect long-term secular trends, and to ascertain cases for ad hoc case-control studies. With slight modifications, these data sets may be used for prompt surveillance of changes in the birth prevalence of malformations, changes that conceivably could be possibly due to the introduction of a teratogen into the environment. A specific logistic approach is suggested, modeled on the New York State Malformation Registry, for prompt detection of changes in rates.

The Biosynthesis of Rat Serum Albumin: V. EFFECT OF PROTEIN DEPLETION AND REFEEDING ON ALBUMIN AND TRANSFERRIN SYNTHESIS

Abstract The effects of protein depletion and repletion on the rate of albumin synthesis and on the levels of albumin in hepatic subcellular particles were measured in intact rats. A second serum protein of hepatic origin, transferrin, was measured simultaneously for comparison. A method capable of assaying albumin synthesis within a 16-min interval was developed in order to permit detection of rapid changes in rates of synthesis; in this procedure the total 14C-albumin content of intrahepatic albumin was divided by the integrated specific radioactivity of intrahepatic free 14C-l-leucine from the time of injection to the time of measurement. This method gave good agreement with measurements based on the circulating 14C-albumin at 2 hours after injection of the tracer. A 10-day period of protein depletion caused a 60 to 70% fall in rate of both albumin and transferrin synthesis, and a 40% fall in the quantities of these proteins bound in hepatic microsomes. Upon refeeding a complete mixture of amino acids by gavage, the level of microsomal albumin increased detectably within 15 min, and the rates of albumin and transferrin synthesis rose 50% within 30 min. This response was not inhibited by actinomycin D. These observations demonstrate the close control of albumin and transferrin synthesis by the amino acid supply in vivo. The amount of albumin in the intracellular albumin pool was observed to reach its normal level even before the circulating albumin level was restored, signifying that hypoalbuminemia can elicit increased synthesis without maintaining a decrease in the intracellular pool.

A recording sorption kinetics apparatus

AbstractAutomatic recordings of the rates of sorption and desorption of gases are obtained by measurement of the volume of the ambient gas under conditions of constant pressure and temperature. The apparatus, which approaches microgram sensitivity, is applicable in the field of diffusion of vapors in polymeric solids (and in obtaining the permeability coefficient). It is especially suited for rapid detection of rate changes and provides operational conveniences for extended measurements. Although exhibiting an over‐sensitivity at low pressures, the apparatus does not share the load‐sensitivity limitations of quartz spiral techniques. As a detector of the kinetics of gas evolution or consumption, the apparatus shows promise of application in other fields of research as well.