Low-Dose CT Image Denoising using Image Decomposition and Sparse Representation

X-ray computed tomography (CT) is now a widely used imaging modality for numerous medical purposes. The risk of high X-ray radiation may induce genetic, cancerous and other diseases, demanding the development of new image processing methods that are able to enhance the quality of low-dose CT images. However, lowering the radiation dose increases the noise in acquired images and hence affects important diagnostic information. This paper contributes an efficient denoising method for low-dose CT images. A noisy image is decomposed into three component images of low, medium and high frequency bands; noise is mainly presented in the medium and high component images. Then, by exploiting the fact that a small image patch of the noisy image can be approximated by a linear combination of several elements in a given dictionary of noise-free image patches generated from noise-free images taken at nearly the same position with the noisy image, noise in these medium and high component images are effectively eliminated.Specifically, we give new solutions for image decomposition to easily control the filter parameters, for dictionary construction to improve the effectiveness and reduce the running-time. Instead of using a large dataset of patches, only a structured small part of patches extracted from the raw data is used to form a dictionary, to be used in sparse coding. In addition, we illustrate the effectiveness of the proposed method in preserving image details which are subtle but clinically important. Experimental results conducted on both synthetic and real noise data demonstrate that the proposed method is competitive with the state-of-the-art methods

Professional development for ESL lecturers – a struggle to integrate ICT into teaching

Information and Communications Technology (ICT) plays a crucial role in our daily life. In fact, students are considered digital citizens and have become accustomed to being always connected to their devices and the Internet. Given the importance ICT plays in our lives, education institutions nowadays have a duty to incorporate ICT into teaching and learning in order to better prepare students for 21st Century skills and careers. Although certain technological equipment may be available in classrooms, there are several external and internal factors that affect the proper implementation of ICT in classrooms. In preparing students to be career-ready, ICT integration is imperative. This paper will discuss factors affecting ESL lecturers’ professional development in terms of ICT application in the classroom. A total of 61 lecturers from 12 non-English-majored universities in Vietnam voluntarily completed this quantitative study’s survey questionnaire. The findings show that although ESL lecturers are aware of the significance of some factors affecting ICT implementation in classrooms, they are struggling to learn, to adapt, and to integrate ICT into their classrooms

Professional development for ESL lecturers – a struggle to integrate ICT into teaching

Information and Communications Technology (ICT) plays a crucial role in our daily life. In fact, students are considered digital citizens and have become accustomed to being always connected to their devices and the Internet. Given the importance ICT plays in our lives, education institutions nowadays have a duty to incorporate ICT into teaching and learning in order to better prepare students for 21st Century skills and careers. Although certain technological equipment may be available in classrooms, there are several external and internal factors that affect the proper implementation of ICT in classrooms. In preparing students to be career-ready, ICT integration is imperative. This paper will discuss factors affecting ESL lecturers’ professional development in terms of ICT application in the classroom. A total of 61 lecturers from 12 non-English-majored universities in Vietnam voluntarily completed this quantitative study’s survey questionnaire. The findings show that although ESL lecturers are aware of the significance of some factors affecting ICT implementation in classrooms, they are struggling to learn, to adapt, and to integrate ICT into their classrooms

A hybrid pansharpening approach and multiscale object-based image analysis for mapping diseased pine and oak trees

We developed a multiscale object-based classification method for detecting diseased trees (Japanese Oak Wilt and Japanese Pine Wilt) in high-resolution multispectral satellite imagery. The proposed method involved (1) a hybrid intensity-huesaturation smoothing filter-based intensity modulation (IHS-SFIM) pansharpening approach to obtain more spatially and spectrally accurate image segments; (2) synthetically oversampling the training data of the 'Diseased tree' class using the Synthetic Minority Over-sampling Technique (SMOTE); and (3) using a multiscale object-based image classification approach. Using the proposed method, we were able to map diseased trees in the study area with a user's accuracy of 96.6% and a producer's accuracy of 92.5%. For comparison, the diseased trees were mapped at a user's accuracy of 84.0% and a producer's accuracy of 70.1% when IHS pansharpening was used alone and a single-scale classification approach was implemented without oversampling the 'Diseased tree' class

Improving Tropical Forest Mapping using Combination of Optical and Microwave Data of ALOS

[ABSTRACT]Optical remote sensing usually has not enough multi-temporal high resolution images to describe phenology of objects for forest mapping in local scale. This paper presents a possibility to improve accuracy of tropical forest mapping by combination of optical and microwave images. Study area is located in the southern part of Vietnam. The first, ALOS/AVNIR-2 images were used to create the forest map, then ALOS/PALSAR single-polarized and dual-polarized images were used to improve the accuracy of the classification result by a combination model. ALOS/PRISM images were also used to make Pan-sharpen images for collecting training data and validation data. Discrimination of Planted Forest and Natural Forest is one of the most important purposes of this study. The overall accuracy of ALOS/AVNIR-2 classification result is 77.0%, while after combining with ALOS/PALSAR, it is increased up to 88.2%. The accuracy is higher than 90% for main forest classes

Magnitude and patterns of severe Plasmodium vivax monoinfection in Vietnam: a 4-year single-center retrospective study

IntroductionInfection with Plasmodium vivax is a recognized cause of severe malaria including deaths. The exact burden and patterns of severe P. vivax monoinfections is however still not well quantified, especially in P. vivax endemic regions. We examined the magnitude and patterns of severe malaria caused by monoinfections of P. vivax and associated predictors among patients admitted to a tertiary care center for malaria in Vietnam.MethodsA retrospective cohort study was conducted based on the patients’ medical records at the Hospital for Tropical Diseases from January 2015 to December 2018. Extracted information included demographic, epidemiologic, clinical, laboratory and treatment characteristics.ResultsMonoinfections with P. vivax were found in 153 (34.5, 95% CI 30.3–39.1%) patients of whom, uncomplicated and severe malaria were documented in 89.5% (137/153, 95% CI 83.7–93.5%) and 10.5% (16/153, 95% CI 6.5–16.3%), respectively. Patterns of severe malaria included jaundice (8 cases), hypoglycemia (3 cases), shock (2 cases), anemia (2 cases), and cerebral malaria (1 case). Among 153 patients, 73 (47.7%) had classic malaria paroxysm, 57 (37.3%) had >7 days of illness at the time of admission, and 40 (26.1%) were referred from other hospitals. A misdiagnosis as having other diseases from malaria cases coming from other hospitals was up to 32.5% (13/40). Being admitted to hospital after day 7th of illness (AOR = 6.33, 95% CI 1.14–35.30, p = 0.035) was a predictor of severe malaria. Severe malaria was statistically associated with longer hospital length of stay (p = 0.035). Early and late treatment failures and recrudescence were not recorded. All patients recovered completely.DiscussionThis study confirms the emergence of severe vivax malaria in Vietnam which is associated with delayed hospital admission and increased hospital length of stay. Clinical manifestations of P. vivax infection can be misdiagnosed which results in delayed treatment. To meet the goal of malaria elimination by 2030, it is crucial that the non-tertiary hospitals have the capacity to quickly and correctly diagnose malaria and then provide treatment for malaria including P. vivax infections. More robust studies need to be conducted to fully elucidate the magnitude of severe P. vivax in Vietnam

Tannins: Extraction from Plants

The chapter presents mainly on different extraction methods of tannin. Some technical means required for effective extraction are also presented, for example, collection and treatment of plant and drying and storage of plant. Opportunity and challenges in application of extraction methods are also exhibited in the chapter

Using Online Games in Teaching: A Bibliometric Analysis

This paper aims to study an overview of the using online games in teaching based on the Scopus data source from January 2016 to July 2023. The PRISMA model is used to guide the selection of articles. After selection and consideration, 19 scientific articles were included for analysis. The author analyzes information such as number of research articles, country, author, citations, keywords. The results showed that the number of research articles on the use of online games in teaching is increasing, in which the article “Using online game-based platforms to improve student performance and engagement in histology teaching" of the authors Felszeghy S. et al. (2019) most influential with a citation index of 81. Student, learning, online, games are keywords that often appear in the articles analyzed. Therefore, through systematic review research to help educational researchers, teachers identify important information about the use of online games in teaching so that they can guide future studies

An analysis of forest biomass changes using geospatial tools and ground survey data: a case study in Yok Don national park, Central Highlands of Vietnam

Vietnam conducts a national forest survey every five years using optical satellite imagery as Landsat, SPOT satellites and ground survey data. However, estimation of change in biomass due to change in forest types has not been of research interest despite of its importance in the face of climate change and applicability for REDD implementation. In this study, we used SPOT HRV satellite data of 2004, 2011 and ground survey data for analysis of changes in biomass of forest cover in Yok Don National Park, Central Highlands of Vietnam. This method has been effectively employed for mapping of land cover with overall classification accuracy of 84.30% to 86.63%. The results demonstrated that between 2004 and 2011, the biomass of Evergreen broad leaved rich forest decreased by 2.95 Megatons, biomass of the Evergreen broad leaved medium forest decreased by 0.09 Mega tons and biomass of the Dry open dipterocarps medium forest decreased 2.20 Mega tons. In that period, biomass of the Evergreen broad-leavedpoor forest increased by 0.02 Mega tons and biomass of the Dry open dipterocarps-poor forest increased by 0.91 Mega tons.References Bao Huy, 2008: Methodology for research on CO2 sequestration in natural forests to join the program of reducing emission from deforestation and degradation-REDD. Journal of Agriculture and Rural Development, MARD, 2008, pp. 1-10. Bhishma, P. et al., 2010: Forest carbon stock measurement-Guidelines for measuring carbon stocks in community-managed forest. Asia Network for Sustainable Agriculture and Bioresource (ANSAB), 79 pp. Brown, S., 1997. Estimating biomass and biomass change of tropical forests: a Primer. FAO Forestry paper–134.ISBN 92-5-103955-0. Brown, S., 2002: Measuring carbon in forests: current status and future challenges. Environmental Pollution, 116(3): 363-372.. Canh N. 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Published by the United Nations Educational, Scientific and Cultural Organization. ISBN 92-3-001046-4 LC No.  72-96442, 1973, 102pp. UN-REDD in Vietnam programme, 2012: Guidelines on Destructive Measurement for Forest Biomass Estimation for technical staff use. (Version for discussion). UN-REDD Vietnam Programme, 2012: Tree allometric equation development for estimation of forest above-ground biomass in Viet Nam. Part A - Introduction and Background of the Study Viet Nam.