Кафедра терапевтичної стоматології
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Item Crystallographic study. Caries-protective properties оf oral fluid of Kharkiv population(2024-02-22) Garmash, Olga; Ryabokon, Evgen; Baglyk, Tatyana; Steblianko, LiudmylaItem Creation of a tooth model with noncarious cervical lesions for analysis by the finite element analysis(2021-10) Zaverukha, YaroslavaItem Experience of distance learning in english-speaking students(2021-04) Воропаєва, Л.В.; Крючко, А.І.; Жданова, Н.О.; Voropaieva, L.; Kriuchko, A.; Zhdanova, N.Distance learning is a means of obtaining education in a certain specialty at a distance from the educational institution. Advanced educational computer programs and platforms have appeared, with the help of which distance education has gained opportunities for closer communication between teachers and English-speaking students, who can receive certain special knowledge and control over their practical application even from their native countries.Item A Fast Noniterative Visually Lossless Compression of Dental Images Using AGU-M Coder(2021) Krylova, Olga; Krivenko, S.; Kryvenko, L.; Lukin, V.This paper deals with lossy compression of medical images in dentistry. For this purpose, we use AGU-M coder based on discrete cosine transform. A peculiarity of the proposed approach is that visually lossless compression is carried out without iterations and, due to this, in a fast way. Invisibility of introduced distortions and/or artifacts is provided by a proper setting of a fixed scaling factor that controls compression. This allows reaching a desired quality of compressed images characterized by PSNR-HVS-M. Experiments are performed for a set of dental images produced by Morita imaging system. Image visual quality has been analyzed by a group of dentistry experts. It is shown that the proposed approach provides several benefits compared to earlier designed counterparts, in particular, a larger compression ratio.Item Analysis of Noise Properties in Dental Images(2020) Abramova, V.; Krivenko, S.; Lukin, V.; Krylova, OlgaImages used in medicine are often noisy. Noise might originate from different factors and it usually degrades image quality leading to less reliable diagnostics. There are stages and the corresponding methods of image processing for which it is extremely desired to know image characteristics to take them into account. In particular, this relates to dental images for which noise is clearly seen and its properties can differ from traditional assumptions if nonlinear operations are carried out to improve visual appearance of acquired images. In this paper, we apply several known (earlier designed) approaches to automatic (blind) estimation of noise statistical and spectral characteristics. It is shown that noise in dental images is spatially correlated and signal dependent with specific dependence. The obtained estimates of noise parameters demonstrate that signal-dependent component is prevailing and the term proportional to squared intensity is present. This can be a serious problem for many image processing techniques.Item Prediction of Visual Quality Metrics in Lossy Image Compression(2020) Krivenko, S.; Li, F.; Lukin, V.; Vozel, B.; Krylova, OlgaImages of different origin are widely used nowadays in various applications including medical diagnostic systems, remote sensing, etc. Due to modern tendency to improve imaging system resolution and increase image size, it has often become necessary to compress images before their storage and transferring via communication lines. Lossy compression is mostly employed for this purpose and an important task for it is to find and provide an appropriate compromise between compression ratio and quality of compressed data, in the first order, image visual quality. This paper considers an approach to predicting visual quality characterized by the metrics MSEHVSM or, equivalently, PSNR-HVS-M for the coder AGU based on discrete cosine transform (DCT). It is demonstrated that it is possible to estimate MSEHVSM in a limited number of 8x8 pixel blocks and then to predict this metric for the entire image for the considered coder. The influence of image content and the number of analyzed blocks is studied. It is shown that 500 or 1000 blocks are usually enough to carry out prediction with appropriate accuracy.Item Visually Lossless Compression of Dental Images(2019) Lukin, V.; Krivenko, S.; Krylova, OlgaIt has become a standard practice to use images in medicine. Due to increasing resolution, their size often occurs to be large and, then, necessity to compress them efficiently before storage and/or transmission arises. Since compression ratio of lossless compression is frequently limited, one has to apply lossy compression. Then, a problem of providing an acceptable quality to retain diagnostic value of compressed data appears. This paper deals with analyzing opportunities to perform this in non- iterative way for dental medical images for two versions of a coder based on discrete cosine transform (DCT) – AGU and AGU-M. It is demonstrated that mean squared error (MSE) and MSE modified with taking into account peculiarities of human vision system (MSEHVS) of distortions due to lossy compression can be predicted before starting compression itself. Then, a desired quantization step (QS) for AGU or scaling factor (SF) for AGU-M can be adjusted to provide a desired quality. Regression uses statistics of alternating current (AC) DCT coefficients calculated in 300…500 8x8 pixel blocks to predict output metrics using fitting curves in preliminary obtained scatter-plots.Item Smart Lossy Compression of Images Based on Distortion Prediction(2018) Krivenko, S.; Krylova, Olga; Bataeva, E.; Lukin, V.Images of different origin are used nowadays in numerous applications spreading the tendency of world digitalization. Despite increase of memory of computers and other electronic carriers of information, amount of memory needed for saving and managing digital data (images and video in the first order) increases faster making crucial the task of their efficient compression. Efficiency means not only appropriate compression ratio but also appropriate speed of compression and quality of compressed images. In this paper, we analyze how this can be reached for coders based on discrete cosine transform (DCT). The novelty of our approach consists in fast and simple analysis of DCT coefficient statistics in a limited number of 8x8 pixel blocks with further rather accurate prediction of mean square error (MSE) of introduced distortions for a given quantization step. Then, a proper quantization step can be set with ensuring the condition that MSE of introduced errors is not greater than a preset value to provide a desired quality. In this way, multiple compressions/decompressions are avoided and the desired quality is provided quickly and with appropriate accuracy. We present examples of applying the proposed approach.Item Visually Lossless Compression of Retina Images(2018) Krivenko, S.; Lukin, V.; Krylova, Olga; Shutko, V.Item Association between RANKL rs9594759 and IL10 rs1800896 gene polymorphisms and deciduous tooth eruption terms in ukrainians born macrosomic(2020) Гармаш, Ольга Володимирівна; Россоха, З.І.; Горовенко, Н.І.; Garmаsh, Olga; Rossokha, Z.; Gorovenko, N.The aim: The article deals with analyzing the influence of polymorphic variants of CYP19A1 [rs2414096, rs936306], ESR1 [rs2234693, rs9340799], IL1 [rs1143627], IL6 [rs1800796], IL10 [rs1800896] and RANKL [rs959389] genes on deciduous tooth eruption terms in individuals born macrosomic. Materials and methods: 171 individuals participated in the multi-stage study (144 macosomic-at-birth individuals and 27 normosomic-at-birth persons). This study included only persons who have preserved information about the timing of deciduous tooth eruption – 159 persons (aged from 4 to 55 years), male and female (male / female ratio was 1.5 / 1). Results and conclusions: The presence of the G allele in CYP19A1 [rs2414096] gene and the -351 A allele in ESR1 [rs9340799] gene were found to be risk factors for fetalmacrosomia formation. The research revealed an association of RANKL [rs9594759] gene variants which is a multiplicative model of inheritance and IL-10 [rs1800896], an overdominant model of inheritance, with an increased risk of tooth delay. Besides the variants of RANKL [rs9594759] and IL-10 [rs1800896] genes a multidirectional modifying effect on the timing of tooth eruption in macrosomic-at-birth individuals made the variant of CYP19A1 [rs2414096] gene – a significant dominant and over-dominant model of inheritance. Further analysis of intergenic interactions will facilitate the application of the obtained results in clinical practice by creating a molecular profile of individuals with deviations in the tooth eruption timing.