Search results for "frequency [modulation]"
showing 10 items of 569 documents
The reference frequency distributions of daily relative sunshine from different locations
1984
Abstract In some applications the relative sunshine distribution curves are very usefull. The present work tends to provide the above frequency distributions for the Italian area, using the daily data of eleven stations. A preliminary compatibility test is applied in order to verify if a dependence on location exist and it is deduced that the area referring to the various locations is statistically compatible with a few exceptions. Therefore, it is possible to give generalized frequency distributions curves which can be considered reference curves for all Italian locations. The empirical distributions are also compared with the calculated ones by the method of Bendt et al. and a good agreem…
The actual management of colorectal liver metastases
2020
Colorectal cancer is one of the most frequent cancers in the world and between 50% and 60% of patients will develop colorectal liver metastases (CRLM) during the disease. There have been great improvements in the management of CRLM during the last decades. The combination of modern chemotherapeutic and biological systemic treatments with aggressive surgical resection strategies is currently the base for the treatment of patients considered unresectable until few years ago. Furthermore, several new treatments for the local control of CRLM have been developed and are now part of the arsenal of multidisciplinary teams for the treatment of these complex patients. The aim of this review was to s…
Characterization of Radio Frequency Echo using frequency sweeping and power analysis
2014
International audience; Coupling between repeater's antennas, called Radio Frequency Echo (RFE) deteriorates signal quality and compromises system stability. If the channel insulation is insufficient, the power in the closed-loop raises with time according to the gain margin value. Multiple methods of echo cancellation exists. Generally, these techniques are based on correlation calculation and adaptive filtering. However, their efficiency and algorithm's convergence speed are calling into question under signal's modulation and real-time constraints, specially with narrow band signals having frequency hopping as GSM or TETRA. This paper describes a real time method of RFE detection and esti…
Secondary implant stability outcome of immediate versus late placed variable-thread implants in the maxilla. A retrospective cohort study
2017
BACKGROUND The healing of xenograft augmentated intra-alveolar gaps following immediate implant placement (IMIP) after tooth extraction is likely to differ in time and density compared to the native bone part that directly contacts the implant. MATERIAL AND METHODS Secondary implant stability (SIS) data recorded 2-3 months following a late implant placement protocol (LIP) (n= 43) and 6-8 months following an immediate implant placement protocol (IMIP) (n=33) of variable-thread implants (Nobel Active™) in the maxilla were retrospectively collected from files of 63 patients (42 females, 21 males). Statistical analysis was performed using a generalized estimating equation model (GEE). Data spli…
Partial Information Decomposition in the Frequency Domain: Application to Control Mechanisms of Heart Rate Variability at Rest and During Postural St…
2020
We exploit a recently proposed framework for assessing causal influences in the frequency domain to construct the partial information decomposition (PID) for informational circuits of three variables, thus obtaining the spectral decomposition of redundancy, synergy and unique information. The approach is applied to heart period (HP), systolic pressure (SP) and respiration (RESP) variability series measured in healthy subjects in baseline and head up tilt conditions. Integrating the informational quantities in the respiratory band, the total influence from RESP to HP does not change in the two conditions. However, we find that in baseline RESP causes HP mostly through the direct pathway desc…
Influence of the gaze-stabilizing eye movements on the quality of the retinal image of the human eye
2000
In this work we have studied the influence of the gaze stabilizing movements of the eye on the quality of the retinal image of the human eye obtained by double pass methods. The results obtained agree with the expected differences between the coherent and incoherent behaviour of the optical system of the eye. The movements-free retinal image is obtained from a typical retinal image by considering a filter function in the frequency domain which characterizes the effect of the considered movements.
Multiscale Model Selection for High-Frequency Financial Data of a Large Tick Stock by Means of the Jensen–Shannon Metric
2014
Modeling financial time series at different time scales is still an open challenge. The choice of a suitable indicator quantifying the distance between the model and the data is therefore of fundamental importance for selecting models. In this paper, we propose a multiscale model selection method based on the Jensen–Shannon distance in order to select the model that is able to better reproduce the distribution of price changes at different time scales. Specifically, we consider the problem of modeling the ultra high frequency dynamics of an asset with a large tick-to-price ratio. We study the price process at different time scales and compute the Jensen–Shannon distance between the original…
Using plot soil loss distribution for soil conservation design
2011
Abstract Soil conservation design is generally based on the estimation of average annual soil loss but it should be developed taking into account storms of a given return period. However, use of frequency analysis in soil erosion studies is relatively limited. In this paper, an investigation on statistical distribution of soil loss measurements was firstly carried out using a relatively high number of simultaneously operating plots of different lengths, λ (11, 22, 33 and 44 m) at the experimental station of Sparacia (southern Italy). Using a simple normalization technique, the analysis showed that the probability distribution of the normalized soil loss is independent of both the scale leng…
Sorafenib for Hepatocellular Carcinoma: From Randomized Controlled Trials to Clinical Practice.
2015
Hepatocellular carcinoma is a challenging malignancy of global importance. It is the sixth most common solid malignancy and the third leading cause of cancer-related death, worldwide. Curative treatments at early stages include liver transplantation, resection and percutaneous ablation, while transarterial chemoembolization can improve survival in patients with intermediate tumor stage. Patients with mild, related symptoms and/or macrovascular invasion or extrahepatic spread are classified under the advanced stage. The standard of care in this group is sorafenib, an inhibitor of Raf kinase and vascular endothelial growth factor receptor, whose effectiveness has been proven by 2 recent rando…
Association of extent of cannabis use and psychotic like intoxication experiences in a multi-national sample of first episode psychosis patients and …
2021
AbstractBackgroundFirst episode psychosis (FEP) patients who use cannabis experience more frequent psychotic and euphoric intoxication experiences compared to controls. It is not clear whether this is consequent to patients being more vulnerable to the effects of cannabis use or to their heavier pattern of use. We aimed to determine whether extent of use predicted psychotic-like and euphoric intoxication experiences in patients and controls and whether this differs between groups.MethodsWe analysed data on patients who had ever used cannabis (n = 655) and controls who had ever used cannabis (n = 654) across 15 sites from six countries in the EU-GEI study (2010–2015). We used multiple regres…