scholarly journals A New Study of Blind Deconvolution with Implicit Incorporation of Nonnegativity Constraints

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Ke Chen ◽  
Simon P. Harding ◽  
Bryan M. Williams ◽  
Yalin Zheng

The inverse problem of image restoration to remove noise and blur in an observed image was extensively studied in the last two decades. For the case of a known blurring kernel (or a known blurring type such as out of focus or Gaussian blur), many effective models and efficient solvers exist. However when the underlying blur is unknown, there have been fewer developments for modelling the so-called blind deblurring since the early works of You and Kaveh (1996) and Chan and Wong (1998). A major challenge is how to impose the extra constraints to ensure quality of restoration. This paper proposes a new transform based method to impose the positivity constraints automatically and then two numerical solution algorithms. Test results demonstrate the effectiveness and robustness of the proposed method in restoring blurred images.

2020 ◽  
pp. 99-104
Author(s):  
O.S. Krotova ◽  
I.V. Moskalev ◽  
L.A. Khvorova ◽  
O.M. Nazarkina

The paper is devoted to the development and implementation of effective models of medical data classification by text mining for decision support in the diagnosis of pulmonological diseases in children and adolescents of the Altai Territory. Medical data contains important information about patients. Test results are usually retained as structured data, but some data are retained in the form of natural language texts (medical history, the results of physical examination, and the results of other examinations). The paper assesses the quality of the developed methods for extracting information from clinical texts. An assessment of the method for the automatic diagnosis of pulmonological diseases in a test sample is conducted. The most informative features, as well as suitable machine learning methods for classifying patients by disease groups, are identified. Many tasks arising in clinical practice can be automated by applying methods for intelligent analysis of structured and unstructured data that will lead to improvement of the healthcare quality. The results of the research indicate the prospect of using models to support decisionmaking in the primary diagnosis of pulmonological diseases in children and adolescents of the Altai Territory.


2019 ◽  
Vol 9 (01) ◽  
pp. 47-54
Author(s):  
Rabbai San Arif ◽  
Yuli Fitrisia ◽  
Agus Urip Ari Wibowo

Voice over Internet Protocol (VoIP) is a telecommunications technology that is able to pass the communication service in Internet Protocol networks so as to allow communicating between users in an IP network. However VoIP technology still has weakness in the Quality of Service (QoS). VOPI weaknesses is affected by the selection of the physical servers used. In this research, VoIP is configured on Linux operating system with Asterisk as VoIP application server and integrated on a Raspberry Pi by using wired and wireless network as the transmission medium. Because of depletion of IPv4 capacity that can be used on the network, it needs to be applied to VoIP system using the IPv6 network protocol with supports devices. The test results by using a wired transmission medium that has obtained are the average delay is 117.851 ms, jitter is 5.796 ms, packet loss is 0.38%, throughput is 962.861 kbps, 8.33% of CPU usage and 59.33% of memory usage. The analysis shows that the wired transmission media is better than the wireless transmission media and wireless-wired.


2020 ◽  
Vol 48 (4) ◽  
pp. 45-111
Author(s):  
A. F. Shepetkin

A new algorithm for constructing orthogonal curvilinear grids on a sphere for a fairly general geometric shape of the modeling region is implemented as a “compile-once - use forever” software package. It is based on the numerical solution of the inverse problem by an iterative procedure -- finding such distribution of grid points along its perimeter, so that the conformal transformation of the perimeter into a rectangle turns this distribution into uniform one. The iterative procedure itself turns out to be multilevel - i.e. an iterative loop built around another, internal iterative procedure. Thereafter, knowing this distribution, the grid nodes inside the region are obtained solving an elliptic problem. It is shown that it was possible to obtain the exact orthogonality of the perimeter at the corners of the grid, to achieve very small, previously unattainable level of orthogonality errors, as well as make it isotropic -- local distances between grid nodes about both directions are equal to each other.


Author(s):  
H Eyigor ◽  
E A Cetinkaya ◽  
D T Coban ◽  
G Ozturk ◽  
Ö Erdem

Abstract Objective External dacryocystorhinostomy is thought to cause mucociliary dysfunction by damaging the mucosa, in turn affecting ciliary activity and mucus quality. This study investigated the effect of external dacryocystorhinostomy on sinonasal function. Methods Patients scheduled for unilateral external dacryocystorhinostomy who underwent endoscopic nasal examination and paranasal sinus computed tomography were included in this study. A saccharine test was performed on the planned surgical side and the mucociliary clearance time was determined. The sinonasal quality of life was measured in all patients, pre-operatively and at six months post-operatively, using the Sino-Nasal Outcome Test-22. The Lund–Kennedy endoscopic score was also determined in all patients, both pre- and post-operatively. Results The study comprised 28 patients (22 females and 6 males). A statistically significant difference was found between the pre- and post-operative saccharine test results (p = 0.006), but not between the pre- and post-operative Sino-Nasal Outcome Test-22 scores (p > 0.05). Conclusion This study is one of only a few to investigate the effect of external dacryocystorhinostomy on sinonasal function. The results showed that external dacryocystorhinostomy impairs mucociliary clearance. The surgical procedure is well tolerated and does not significantly change nasal symptom scores.


2021 ◽  
pp. 004051752110308
Author(s):  
Yang Liu ◽  
Zhong Xiang ◽  
Xiangqin Zhou ◽  
Zhenyu Wu ◽  
Xudong Hu

Friction between the tow and tool surface normally happens during the tow production, fabric weaving, and application process and has an important influence on the quality of the woven fabric. Based on this fact, this paper studied the influence of tension and relative velocity on the three kinds of untwisted-glass-fiber tow-on-roller friction with a Capstan-based test setup. Furthermore, an improved nonlinear friction model taking both tension and velocity into account was proposed. According to statistical test results, firstly, the friction coefficient was found to be positively correlated with tension and relative velocity. Secondly, tension and velocity were complementary on the tow-on-roller friction behavior, with neither being superior to the other. Thirdly, an improved model was found to present well the nonlinear characteristics between friction coefficient and tension and velocity, and predicational results of the model were found to agree well with the observations from Capstan tests.


2013 ◽  
Vol 380-384 ◽  
pp. 1143-1146
Author(s):  
Xiang Guo Liu

The paper researches the parametric inversion of the two-dimensional convection-diffusion equation by means of best perturbation method, draw a Numerical Solution for such inverse problem. It is shown by numerical simulations that the method is feasible and effective.


2008 ◽  
Vol 54 (11) ◽  
pp. 1872-1882 ◽  
Author(s):  
Eva Nagy ◽  
Joseph Watine ◽  
Peter S Bunting ◽  
Rita Onody ◽  
Wytze P Oosterhuis ◽  
...  

Abstract Background: Although the methodological quality of therapeutic guidelines (GLs) has been criticized, little is known regarding the quality of GLs that make diagnostic recommendations. Therefore, we assessed the methodological quality of GLs providing diagnostic recommendations for managing diabetes mellitus (DM) and explored several reasons for differences in quality across these GLs. Methods: After systematic searches of published and electronic resources dated between 1999 and 2007, 26 DM GLs, published in English, were selected and scored for methodological quality using the AGREE Instrument. Subgroup analyses were performed based on the source, scope, length, origin, and date and type of publication of GLs. Using a checklist, we collected laboratory-specific items within GLs thought to be important for interpretation of test results. Results: The 26 diagnostic GLs had significant shortcomings in methodological quality according to the AGREE criteria. GLs from agencies that had clear procedures for GL development, were longer than 50 pages, or were published in electronic databases were of higher quality. Diagnostic GLs contained more preanalytical or analytical information than combined (i.e., diagnostic and therapeutic) recommendations, but the overall quality was not significantly different. The quality of GLs did not show much improvement over the time period investigated. Conclusions: The methodological shortcomings of diagnostic GLs in DM raise questions regarding the validity of recommendations in these documents that may affect their implementation in practice. Our results suggest the need for standardization of GL terminology and for higher-quality, systematically developed recommendations based on explicit guideline development and reporting standards in laboratory medicine.


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