1,298 research outputs found
Multiproduct Uniform Polar Quantizer
The aim of this paper is to reduce the complexity of the unrestricted uniform polar quantizer (UUPQ), keeping its high performances. To achieve this, in this paper we propose the multiproduct uniform polar quantizer (MUPQ), where several consecutive magnitude levels are joined in segments and within each segment the uniform product quantization is performed (i.e. all levels within one segments have the same number of phase levels). MUPQ is much simpler for realization than UUPQ, but it achieves similar performances as UUPQ. Since MUPQ has low complexity and achieves much better performances than the scalar uniform quantizer, it can be widely used instead of scalar uniform quantizers to improve performances, for any signal with the Gaussian distribution
Semilogarithmic Nonuniform Vector Quantization of Two-Dimensional Laplacean Source for Small Variance Dynamics
In this paper high dynamic range nonuniform two-dimensional vector quantization model for Laplacean source was provided. Semilogarithmic A-law compression characteristic was used as radial scalar compression characteristic of two-dimensional vector quantization. Optimal number value of concentric quantization domains (amplitude levels) is expressed in the function of parameter A. Exact distortion analysis with obtained closed form expressions is provided. It has been shown that proposed model provides high SQNR values in wide range of variances, and overachieves quality obtained by scalar A-law quantization at same bit rate, so it can be used in various switching and adaptation implementations for realization of high quality signal compression
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Non-invasive imaging of subsurface paint layers with optical coherence tomography
Optical coherence tomography (OCT) systems are fast scanning infrared Michelson interferometers designed for the non-invasive examination of the interiors of the eye and subsurface structures of biological tissues. OCT has recently been applied to the non-invasive examinations of the stratigraphy of paintings and museum artefacts. So far this is the only technique capable of imaging non-invasively the subsurface structure of paintings and painted objects. Unlike the traditional method of paint cross-section examination where sampling is required, the non-invasive and non-contact nature of the technique enables the examination of the paint cross-section anywhere on a painting, as there is no longer an issue with conservation ethics regarding the taking of samples from historical artefacts. A range of applications of the technique including the imaging of stratigraphy of paintings and painted artefacts, the imaging of underdrawings to the analysis of the optical properties of paint and varnish layers is presented. Future projects on the application of OCT to art conservation are discussed
Tolerability of Induction Chemotherapy Dosing Practices in Acute Myeloid Leukemia Patients
For patients with high body surface areas (BSA), differing chemotherapy dosing strategies have been utilized in attempts to reduce toxicity. In a retrospective evaluation, we compared the effects of chemotherapy dosing in acute myeloid leukemia patients with high BSA (\u3e2 m2) who received capped doses (n = 12) to those who received uncapped doses (n = 24), and to patients with BSA ≤ 2 m2 (n = 42). There were no statistically significant differences among groups (BSA ≤ 2 m2, BSA \u3e 2 m2 capped, and BSA \u3e 2 m2 uncapped) in the incidences of febrile neutropenia (85.7, 66.7, and 75.0%, respectively, p = 0.29), bacteremia (19.0, 8.3, and 16.7%, respectively, p = 0.68), mucositis (42.8, 50.0, and 41.7%, respectively, p = 0.88) or nausea/vomiting (47.6, 33.3, and 37.5, respectively, p = 0.57). Results suggest delivery of unadjusted chemotherapy based on actual body weight is likely safe in hematological malignancies
Log-Polar Quantizer with the Embedded G.711 Codec
In this paper a new two-dimensional vector quantizer for memoryless Gaussian source, realized in polar coordinates, is proposed. The G.711 codec is embedded in our vector quantizer, and therefore our vector quantizer is compatible with the G.711 codec. It is simple for realization and it has much better performances, compared to the G.711 codec, such as much higher SQNR (signal-to-quantization noise ratio) for the same bit-rate, or bit-rate decrease for the same SQNR. The G.711 codec is widely used in many systems, especially in PSTN (public switched telephone network). Due to compatibility with the G.711 standard, our vector quantizer can be realized with simple software modification of the existing the G.711 codec, and therefore it can be very easily implemented in PSTN and other systems. So, small investments are needed for wide implementation of our model, but significant improvement of performances can be obtained
Design and standalone characterisation of a capacitively coupled HV-CMOS sensor chip for the CLIC vertex detector
The concept of capacitive coupling between sensors and readout chips is under
study for the vertex detector at the proposed high-energy CLIC electron
positron collider. The CLICpix Capacitively Coupled Pixel Detector (C3PD) is an
active High-Voltage CMOS sensor, designed to be capacitively coupled to the
CLICpix2 readout chip. The chip is implemented in a commercial nm HV-CMOS
process and contains a matrix of square pixels with m
pitch. First prototypes have been produced with a standard resistivity of
cm for the substrate and tested in standalone mode. The
results show a rise time of ns, charge gain of mV/ke and
e RMS noise for a power consumption of W/pixel. The
main design aspects, as well as standalone measurement results, are presented.Comment: 13 pages, 13 figures, 2 tables. Work carried out in the framework of
the CLICdp collaboratio
Side effects assessment in glicolyc acid peelings in patients with acne type I
Chemical peeling implies the application of a chemical agent to the skin, which causes controlled destruction of a part or the entire epidermis, with or without the dermis, leading to exfoliation and removal of superficial lesions, followed by regeneration of new epidermal and dermal tissues. The present study was directed toward safety concerns associated with superficial chemical peeling with glycolic acid (GA) in different concentrations at patients with acne tip I. A sample of 90 patients of either sex, aged between 17 to 21 years, were included in the study and submitted to superficial chemical peeling for acne vulgaris. The study lasted eight weeks and peeling sessions were carried out in each patient. Tolerance to the procedure and any undesirable effects noted during these sessions were recorded. For data statistical analysis and interpretation of results, software program SPSS version 13 was used. Results were expressed through the descriptive statistics, as simple frequencies and percentages, while for establishing of statistically significant differences, in use was Friedman's test of significance. Almost all the patients tolerated the procedure well. Of totally 90 patients, only six, at the end of therapy experienced hard erythema, only ten, at the end of therapy experienced hard desquamation and only eleven, at the end of therapy experienced hard sensation of pulling of facial skin. Chemical peeling with glycolic acid is a well tolerated and safe treatment modality in acne type I. © 2011 Association of Basic Medical Sciences of FBIH
Comparison of AlphaLISA and RIA assays for measurement of wool cortisol concentrations
Radioimmunoassay (RIA) methods have always represented a technique of choice for the determination of steroids in biological samples. The Amplified Luminescent Proximity Homogenous Assay-Linked Immunosorbent Assay (AlphaLISA) is now emerging as the new-generation immunoassay technology that does not require washing/separation steps. The aim of this study was to adapt the Perkin-Elmer's AlphaLISA kit for wool cortisol and compare it with a RIA wool cortisol assay. Wool from lambs, 35 at birth (A0) and 54 at two months old (A2), was collected and each extract was evaluated for wool cortisol concentrations (HCC) both by RIA and AlphaLISA immunoassay. The two methods showed good precision, sensitivity and specificity for determining HCC. Both methods were able to detect significant differences between the high and the low HCC assessed in lambs at A0 and A2 (P < 0.01). The HCC assessed with RIA were significantly higher than those assessed with AlphaLISA (P < 0.01). Moreover, the correlation between HCC measured using the AlphaLISA and RIA methods was strong (r = 0.878). The regression analyses show a constant and not proportional error. This could be due to the diversity in the dosage steps and to the diversity of the molecules used in the two methods. Results support the validity of using AlphaLISA as an alternative method to RIA for the quantification of cortisol in sheep wool and considering the performances showed it has a great potential to be further applied as an excellent tool to evaluate HCC in samples derived from animal species
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