دانلود و نمایش مقالات مرتبط با کنتراست::صفحه 1
بلافاصله پس از پرداخت دانلود کنید

با سلام خدمت کاربران در صورتی که با خطای سیستم پرداخت بانکی مواجه شدید از طریق کارت به کارت (6037997535328901 بانک ملی ناصر خنجری ) مقاله خود را دریافت کنید (تا مشکل رفع گردد). 

نتیجه جستجو - کنتراست

تعداد مقالات یافته شده: 23
ردیف عنوان نوع
1 Effect of red ginseng on visual function and vision-related quality of life in patients with glaucoma
تأثیر جینسنگ قرمز بر عملکرد بینایی و کیفیت زندگی مرتبط با بینایی در بیماران مبتلا به گلوکوم-2021
Background: Red ginseng has been found to improve ocular perfusion and dry eye syndrome in glaucomatous eyes; however, its effects on visual function and vision-related quality of life have not been investigated. This study sought to evaluate the effects of red ginseng on visual function and visionrelated quality of life in glaucoma patients using contrast sensitivity and a questionnaire.
Methods: Participants were randomly assigned to two groups in this prospective, randomized, doubleblind study: in one group, red ginseng was taken first, followed by a placebo, and in the other, placebo was taken first, followed by red ginseng. We measured and compared changes in contrast sensitivity and vision-related quality of life between the two groups. Contrast sensitivity was measured using OPTEC® 6500P, and vision-related quality of life was evaluated using the 25-item National Eye Institute Visual Function Questionnaire. One-way and two-way repeated measure analyses of variance were used for the comparison. Relationships between respective changes in dry eye syndrome and contrast sensitivity were also analyzed.
Results: Daytime contrast sensitivity and ocular pain improved after the administration of red ginseng. Nighttime contrast sensitivity was improved in early or moderate glaucoma. Improved contrast sensitivity was not associated with improvement in dry eye syndrome.
Conclusion: Red ginseng could improve contrast sensitivity and ocular pain in patients with glaucoma. The mechanism underlying improvement in contrast sensitivity appears to be associated with enhanced retinal perfusion or retinal ganglion cell function, but not dry eye syndrome.
Keywords: Panax ginseng | Glaucoma | Dry eye syndrome | Contrast sensitivity | Vision-related quality of life
مقاله انگلیسی
2 The relation between non-GAAP earnings and accounting restatements: Evidence after regulation G
رابطه بین درآمد غیر GAAP و بازپرداخت حسابداری: شواهد پس از مقررات G-2021
Scholarly findings on whether disclosure of Non-GAAP earnings is informative or opportunistic are inconsistent. Since the 2003 implementation of Regulation G, investors can view managements process of adjusting from GAAP earnings to Non-GAAP earnings. This study investigates the information content of Non-GAAP earnings in the context of restatements. The hypotheses of this study are based on the following two propositions. First, the IN formativeness of Non-GAAP earnings is determined by the nature of items excluded from GAAP earnings to derive Non-GAAP earnings (either nonrecurring special items or recurring exclusions). Second, restatements can be used to distinguish between informative and opportunistic Non-GAAP earnings disclosures. My results show that firms with restatements, especially fraud or core earnings restatements, exhibit greater relative use of Non- GAAP earnings disclosures that adjust GAAP earnings for positive other exclusions (recurring expenses). By contrast, disclosures of Non-GAAP earnings derived by excluding nonrecurring expenses (special items) from GAAP earnings are not associated with restatements.
keywords: درآمد غیرقانونی | تسهیلات حسابداری | مدیریت تعهدات | مدیریت فعالیت های واقعی | Non-GAAP earnings | Accounting restatements | Accruals management | Real activities management
مقاله انگلیسی
3 تمایز خونریزی حاصل از افزایش کنتراست با استفاده از CT طیف سنجی با لایه دوگانه در بیماران سکته حاد
سال انتشار: 2021 - تعداد صفحات فایل pdf انگلیسی: 4 - تعداد صفحات فایل doc فارسی: 8
بیماران سکته حاد به مراکز دارای ترومبکتومی(لخته برداری) (TCC) انتقال می یابند و پس از ورود به TCC ، تحت معاینه CT سر قرار می گیرند تا نمره ASPECTS و خونریزی داخل جمجمه آنها ارزیابی شود. تقویت پارانشیمی در بیمارانی که کنتراست یددار یا iodinated را قبل از انتقال دریافت کرده اند، در شبیه سازی خونریزی در این CT و پس از انتقال کمک می کند. دو مورد از کاربرد تصویربرداری طیفی CT به منظور تمایز بین افزایش کنتراست پارانشیمی و خونریزی در این مطالعه گزارش شده است. روش TCC، تصویربرداری با انرژی دوگانه یا لایه دوگانه (طیفی) را برای این گروه بیمار در نظر می گیرد.
کلمات کلیدی: سکته مغزی | تصویربرداری طیفی CT
مقاله ترجمه شده
4 Color Image Enhancement based on Gamma Encoding and Histogram Equalization
بهبود تصویر رنگی بر اساس رمزگذاری گاما و یکسان سازی هیستوگرام-2021
Image Enhancement is used as a preprocessing step in many computer vision applications. It provides enhanced input for other computerized image processing methods. Many preprocessing techniques can be applied to images depending on the application domain. In this paper we are proposing an image enhancement technique for color images that can be used as preprocessing step in many computer vision applications. It can also be used as a data augmentation technique in object detection. Luminance component of images is sometimes not captured by cameras and displayed by monitors properly. To remove this drawback of devices we have used gamma encoding. Four different values of gamma are evaluated depending on the quality of images. Image is then converted into YUV Color space. Y component represents the luminance. U and V components represent color. After that Contrast Limited Adaptive Histogram Equalization is applied to the Y component to improve the contrast of the image. The results are compared with the state-of-the-art methods on the basis of Peak Signal to noise Ratio (PSNR) and Mean Square Error (MSE). Quantitative results show that proposed algorithm results in improved value of PSNR and decreased value of MSE as compared to existing methods. Qualitative comparison is also done and results show improvement over the existing techniques.© 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Materials, Manufacturing and Mechanical Engineering for Sustainable Developments-2020.
Keywords: Histogram | Intensity | Luminance | Contrast stretching
مقاله انگلیسی
5 A mesh-free method for interface problems using the deep learning approach
روشی بدون مش برای مشکلات رابط با استفاده از روش یادگیری عمیق-2020
In this paper, we propose a mesh-free method to solve interface problems using the deep learning approach. Two types of PDEs are considered. The first one is an elliptic PDE with a discontinuous and high-contrast coefficient. While the second one is a linear elasticity equation with discontinuous stress tensor. In both cases, we represent the solutions of the PDEs using the deep neural networks (DNNs) and formulate the PDEs into variational problems, which can be solved via the deep learning approach. To deal with inhomogeneous boundary conditions, we use a shallow neural network to approximate the boundary conditions. Instead of using an adaptive mesh refinement method or specially designed basis functions or numerical schemes to compute the PDE solutions, the proposed method has the advantages that it is easy to implement and is mesh-free. Finally, we present numerical results to demonstrate the accuracy and efficiency of the proposed method for interface problems.
Keywords: Deep learning | Variational problems | Mesh-free method | Linear elasticity | High-contrast | Interface problems
مقاله انگلیسی
6 STrategically Acquired Gradient Echo (STAGE) imaging, part III: Technical advances and clinical applications of a rapid multi-contrast multi-parametric brain imaging method
تصویربرداری گرادیان اکو (STAGE) استراتژیک ، بخش سوم: پیشرفت های فنی و برنامه های بالینی از یک روش تصویربرداری سریع مغزی چند پارامتری سریع با کنتراست-2020
One major thrust in radiology today is image standardization with a focus on rapidly acquired quantitative multi-contrast information. This is critical for multi-center trials, for the collection of big data and for the use of artificial intelligence in evaluating the data. Strategically acquired gradient echo (STAGE) imaging is one such method that can provide 8 qualitative and 7 quantitative pieces of information in 5 min or less at 3 T. STAGE provides qualitative images in the form of proton density weighted images, T1 weighted images, T2* weighted images and simulated double inversion recovery (DIR) images. STAGE also provides quantitative data in the form of proton spin density, T1, T2* and susceptibility maps as well as segmentation of white matter, gray matter and cerebrospinal fluid. STAGE uses vendors product gradient echo sequences. It can be applied from 0.35 T to 7 T across all manufacturers producing similar results in contrast and quantification of the data. In this paper, we discuss the strengths and weaknesses of STAGE, demonstrate its contrast-to-noise (CNR) behavior relative to a large clinical data set and introduce a few new image contrasts derived from STAGE, including DIR images and a new concept referred to as true susceptibility weighted imaging (tSWI) linked to fluid attenuated inversion recovery (FLAIR) or tSWI-FLAIR for the evaluation of multiple sclerosis lesions. The robustness of STAGE T1 mapping was tested using the NIST/NIH phantom, while the reproducibility was tested by scanning a given individual ten times in one session and the same subject scanned once a week over a 12-week period. Assessment of the CNR for the enhanced T1W image (T1WE) showed a significantly better contrast between gray matter and white matter than conventional T1W images in both patients with Parkinsons disease and healthy controls. We also present some clinical cases using STAGE imaging in patients with stroke, metastasis, multiple sclerosis and a fetus with ventriculomegaly. Overall, STAGE is a comprehensive protocol that provides the clinician with numerous qualitative and quantitative images.
Keywords: Quantitative magnetic resonance imaging | Susceptibility weighted imaging | T1 mapping | Quantitative susceptibility mapping | Multi-parametric magnetic resonance imaging | Strategically acquired gradient echo
مقاله انگلیسی
7 Effectiveness assessing of softwares with AI for chest area x-ray images post-processing
ارزیابی اثربخشی نرم افزارها با هوش مصنوعی برای تصاویر اشعه ایکس ناحیه قفسه سینه پس از پردازش-2020
Diagnostic radiology is a branch of medicine describes of ionizing radiation using to study the structure and functions of normal and pathological altered human organs and systems for the prevention and detection of diseases. X-ray irradiation is the most common diagnostic method in Radiology and it makes possible to identify and diagnose diseases and injuries for further treatment of patients. In particular, development of artificial intelligence (AI) has led the creation of different software for X-ray images processing to improve pathologists recognition by operator. At this moment there are lots of means and methods have been developed by different software engineers to find out "the perfect solution" for this problem. Respiratory diseases occupy one of the leading places in Ukraine. The main share of pathologies is acute viral infections, bronchitis, pneumonia and tuberculosis. In one year, about 15.5 million chest X-ray studies perform in Ukraine only for tuberculosis detection. It was the reason to select chest X-ray studies for processing’s effectiveness assessing. For effectiveness assessing we have made quantitative contrast measurements for selected areas on original and processed chest X-ray images.
Keywords: X-ray | tomosynthesis | digital radiology | contrast deviations | AI
مقاله انگلیسی
8 Establishing structure-property localization linkages for elastic deformation of three-dimensional high contrast composites using deep learning approaches
ایجاد پیوندهای محلی سازی ساختار و خاصیت برای تغییر شکل الاستیک کامپوزیت های کنتراست بالا سه بعدی با استفاده از روشهای یادگیری عمیق-2019
Data-driven methods are attracting growing attention in the field of materials science. In particular, it is now becoming clear that machine learning approaches offer a unique avenue for successfully mining practically useful process-structure-property (PSP) linkages from a variety of materials data. Most previous efforts in this direction have relied on feature design (i.e., the identification of the salient features of the material microstructure to be included in the PSP linkages). However due to the rich complexity of features in most heterogeneous materials systems, it has been difficult to identify a set of consistent features that are transferable from one material system to another. With flexible architecture and remarkable learning capability, the emergent deep learning approaches offer a new path forward that circumvents the feature design step. In this work, we demonstrate the implementation of a deep learning feature-engineering-free approach to the prediction of the microscale elastic strain field in a given threedimensional voxel-based microstructure of a high-contrast two-phase composite. The results show that deep learning approaches can implicitly learn salient information about local neighborhood details, and significantly outperform state-of-the-art methods.
Keywords: Materials informatics | Convolutional neural networks | Deep learning | Localization | Structure-property linkages
مقاله انگلیسی
9 Local polynomial contrast binary patterns for face recognition
الگوهای باینری کنتراست چند جمله ای محلی برای تشخیص چهره-2019
We propose a novel face representation model, called the polynomial contrast binary patterns (PCBP), based on the polynomial filters, for robust face recognition. It is assumed that the discrete array of pixel values comes about by sampling an underlying smooth surface in an image. The proposed method effi- ciently estimates the underlying local surface information, which is approximately represented as linear projection coefficients of the pixels in a local patch. The decomposition using polynomial filters can cap- ture rich image information at multiple orientations and frequency bands. This guarantees its robustness to illumination and expression variations. The weighting scheme embeds different discriminative pow- ers of each filter response image. We also propose to carry out a subsequent Fisher linear Discriminant (FLD) on each decomposed image for dimension reduction of features. Our extensive experiments on the public FERET and LFW databases demonstrate that the non-weighted Polynomial contrast binary patterns performs better than most of methods and the weighting scheme further improves the recognition rates. WPCBP + FLD(CD) and WPCBP + FLD(HI) can achieve much competitive or even better recognition perfor- mance compared with the state-of-the-art face recognition methods.
Keywords: Face recognition | Polynomial filters | Local binary patterns | Surface fitting
مقاله انگلیسی
10 A ( k , n ) Threshold Partial Reversible AMBTC-based Visual Cryptography Using One Reference Image
A (k ، n) رمزنگاری تصویری مبتنی بر AMBTC قابل برگشت جزئی با استفاده از یک تصویر مرجع-2019
Recently, Yang et al. introduced a ðk; nÞ approach called Reversible Absolute moment block truncation coding Visual Cryptography Scheme (RAVCS) (Yang et al., 2017) to conceal a secret image into n AMBTC shares. However, a large number of reference images is used in their method. To reduce the number of reference images, a ðk; nÞ PRAVCS using one AMBTC reference image is introduced. In encoding phase, a binary secret image is shared into n AMBTC shadow images according to the base matrices generated by two proposed constructions. In decoding phase, the secret image is recovered by stacking sufficient bitmaps, and the AMBTC reference image is partially recovered as well. When n AMBTC shares are used, losslessly reconstruction for the reference image is obtained. Theoretical analysis and experiments by the proposed method are demonstrated to show the effectiveness. Moreover, Construction 1 has larger contrast, while Construction 2 achieves higher reversibility for more thresholds.
Keywords: Visual cryptography | Block truncation coding | Partial reversible | Meaningful share | Contrast | Reference image
مقاله انگلیسی
rss مقالات ترجمه شده rss مقالات انگلیسی rss کتاب های انگلیسی rss مقالات آموزشی
logo-samandehi
بازدید امروز: 2245 :::::::: بازدید دیروز: 0 :::::::: بازدید کل: 2245 :::::::: افراد آنلاین: 69