Real-time Heart Rate Measurement based on Photoplethysmography using Android Smartphone Camera

Hoan, Nguyen Viet,Park, Jin-Hyeok,Lee, Suk-Hwan,Kwon, Ki-Ryong Korea Multimedia Society 2017 멀티미디어학회논문지 Vol.20 No.2

With the development of smartphone technologies enable photoplethysmogram (PPG) acquisition by camera and heart rate (HR) measurement. This papers presents improved algorithm to extract HR from PPG signal recorded by smartphone camera and to develop real-time PPG signal processing Android application. 400 video samples recorded by Samsung smartphone camera are imported as input data for further processing and evaluating algorithm on MATLAB. An optimized algorithm is developed and tested on Android platform with different kind of Samsung smartphones. To assess algorithm's performance, medical device Beurer BC08 is used as reference. According to related works, accuracy parameters includes 90% number of samples that has relative errors less than 5%, Person correlation (r) more than 0.9, and standard estimated error (SEE) less than 5 beats-per-minutes (bpm).

Synthesis of a Novel Fluorescent Cyanide Chemosensor Based on Photoswitching Poly(pyrene-1-ylmethyl-methacrylate-randommethyl methacrylate-random-methacrylate spirooxazine)

Hoan Minh Tran,Tam Huu Nguyen,Viet Quoc Nguyen,Phuc Huynh Tran,Linh Duy Thai,Thuy Thu Truong,Le-Thu T. Nguyen,Ha Tran Nguyen 한국고분자학회 2019 Macromolecular Research Vol.27 No.1

The photoswitching poly(pyrene-1-ylmethyl-methacrylate-random-methyl methacrylate-random-methacrylate spirooxazine) was synthesized via atom transfer radical polymerization and characterized by proton nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC), Fourier transform infrared (FTIR) spectroscopy, UV-visible spectroscopy, and differential scanning calorimetry (DSC). The obtained copolymer exhibited the capability of erasable and rewritable photoimaging, making it a potential candidate for optical data storage materials. Moreover, the copolymer also showed the sensing ability for cyanide anions effect in aqueous solutions.

Anti-interference Methods using Vector-based GPS Receiver Model

Hoan Nguyen Viet,이석환,권기룡 한국멀티미디어학회 2018 멀티미디어학회논문지 Vol.21 No.5

The Global Positioning System (GPS) has become popular and widely used in many fields from military to civilian applications. However, GPS signals are suffered from interference due to its weak signal over wireless channel. There are many types of interference, such as jamming, blocking multipath, and spoofing, which can mislead the operation of GPS receiver. In this paper, vector-based tracking loop model with integrity check is proposed to detect and mitigate the harmful effect of interference on GPS receiver operation. The suggested methods are implemented in the tracking loop of GPS receiver. As a first method, integrity check with carrier-to-noise ratio (C/No) monitoring technique is applied to detect the presence of interference and prevent contaminated channels out of tracking channels to calculate position. As a second method, a vector-based tracking loop using Extended Kalman Filter with adaptive noise covariance according to C/No monitoring results. The proposed methods have been implemented on simulated dataset. The results demonstrates that the suggested methods significantly mitigate interference of Additive White Gaussian Noise (AWGN) and improve position calculation by 44%.

Real-time Heart Rate Measurement based on Photoplethysmography using Android Smartphone Camera

NGUYEN VIET HOAN,박진혁,이석환,권기룡 한국멀티미디어학회 2017 멀티미디어학회논문지 Vol.20 No.2

With the development of smartphone technologies enable photoplethysmogram (PPG) acquisition by camera and heart rate (HR) measurement. This papers presents improved algorithm to extract HR from PPG signal recorded by smartphone camera and to develop real-time PPG signal processing Android application. 400 video samples recorded by Samsung smartphone camera are imported as input data for further processing and evaluating algorithm on MATLAB. An optimized algorithm is developed and tested on Android platform with different kind of Samsung smartphones. To assess algorithm’s performance, medical device Beurer BC08 is used as reference. According to related works, accuracy parameters includes 90% number of samples that has relative errors less than 5%, Person correlation (r) more than 0.9, and standard estimated error (SEE) less than 5 beats-per-minutes (bpm).

Anti-interference Methods using Vector-based GPS Receiver Mode

Viet, Hoan Nguyen,Lee, Suk-Hwan,Kwon, Ki-Ryong Korea Multimedia Society 2018 멀티미디어학회논문지 Vol.21 No.5

The Global Positioning System (GPS) has become popular and widely used in many fields from military to civilian applications. However, GPS signals are suffered from interference due to its weak signal over wireless channel. There are many types of interference, such as jamming, blocking multipath, and spoofing, which can mislead the operation of GPS receiver. In this paper, vector-based tracking loop model with integrity check is proposed to detect and mitigate the harmful effect of interference on GPS receiver operation. The suggested methods are implemented in the tracking loop of GPS receiver. As a first method, integrity check with carrier-to-noise ratio (C/No) monitoring technique is applied to detect the presence of interference and prevent contaminated channels out of tracking channels to calculate position. As a second method, a vector-based tracking loop using Extended Kalman Filter with adaptive noise covariance according to C/No monitoring results. The proposed methods have been implemented on simulated dataset. The results demonstrates that the suggested methods significantly mitigate interference of Additive White Gaussian Noise (AWGN) and improve position calculation by 44%.

Chemical properties and antioxidant activity of essential oils of Chrysanthemum morifolium Ramat. and Chrysanthemum indicum L. in Vietnam

Thi-Hoan Luong,Dang-Minh-Chanh Nguyen,Thi-Nga Trinh,Viet-Cuong Han,Woo-Jin Jung 한국응용생명화학회 2022 Journal of Applied Biological Chemistry (J. Appl. Vol.65 No.4

In recent years, research into medicinal herbs with antioxidative activities has increased. Chrysanthemum morifolium and Chrysanthemum indicum are aromatic herb plants and that have long been used in traditional Vietnamese medicine. This study aims to evaluate the chemical compositions and antioxidative activities of essential oils hydrodistilled from the flower heads of C. morifolium and C. indicum. The chemical compositions of the essential oils were compared using gas chromatography/mass spectrometry (GC/MS) analysis. The antioxidative activity was determined and evaluated spectroscopically by the 2,2-diphenyl- 1-picrylhydrazyl (DPPH) radical scavenging, metal chelating activity, reducing power, and total antioxidant capacity assays. According to the GC/MS results, chrysanthenone was predominant in the essential oils of both C. morifolium (64.14%) and C. indicum (32.02%). This is the first report of the identification of chrysanthenone as a major constituent of the essential oil of C. morifolium. Both Chrysanthemum oils were also revealed to possess antioxidant potential, exhibiting high antioxidative activities. In particular, the DPPH radical scavenging activities of the C. morifolium and C. indicum oils at a concentration of 100 mg/mL were 76.9 and 83.2%, respectively. The metal chelating values of C. morifolium and C. indicum were 0.85 and 0.76, whereas the reducing power values of that at 100 mg/mL were 0.76 and 0.71, respectively. This study provides the chemical properties of the essential oils of both C. morifolium and C. indicum grown in Vietnam and their potential antioxidant capacity

Real-time Steel Surface Defects Detection Appliocation based on Yolov4 Model and Transfer Learning

김복경,배준희,NGUYEN VIET HOAN,이용은,옥영석 사)한국빅데이터학회 2022 한국빅데이터학회 학회지 Vol.7 No.2

Steel is one of the most fundamental components to mechanical industry. However, the quality of products are greatly impacted by the surface defects in the steel. Thus, researchers pay attention to the need for surface defects detector and the deep learning methods are the current trend of object detector. There are still limitations and rooms for improvements, for example, related works focus on developing the models but don’t take into account real-time application with practical implication on industrial settings. In this paper, a real-time application of steel surface defects detection based on YOLOv4 is proposed. Firstly, as the aim of this work to deploying model on real-time application, we studied related works on this field, particularly focusing on one-stage detector and YOLO algorithm, which is one of the most famous algorithm for real-time object detectors. Secondly, using pre-trained Yolov4-Darknet platform models and transfer learning, we trained and test on the hot rolled steel defects open-source dataset NEU-DET. In our study, we applied our application with 4 types of typical defects of a steel surface, namely patches, pitted surface, inclusion and scratches. Thirdly, we evaluated YOLOv4 trained model real-time performance to deploying our system with accuracy of 87.1 % mAP@0.5 and over 60 fps with GPU processing.

Medicinal Plant Extract and Chitosan Oligomer Antifungal Activities Inhibit Phytophthora capsici

Dang-Minh-Chanh Nguyen,Thi-Hoan Luong,Tien-Chung Nghiem,Van-Viet Nguyen,정우진 한국키틴키토산학회 2023 한국키틴키토산학회지 Vol.28 No.1

This study aims to evaluate antioxidant and antifungal activities from medicinal plant’ methanol extract, chitosan oligomer, and the two combined. Their antioxidative activity was spectroscopically assessed through 2,2-diphenyl-2- picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assays. Alternatively, antifungal activity was determined through Phytophthora capsici's mycelial growth inhibition. DPPH and ABTS radical scavenging activities were observed at 1000 ppm concentrations for Glycyrrhiza uralensis extract (GU, 81.4%, IC50=238.4ppm; 83.5%, 199.5ppm, respectively), chitosan oligomer (ChiO, 64.8%, 438.2ppm; 66.6%, 314.5ppm), and GU+ChiO (78.3%, 329.7 ppm; 75.2%, 254.0 ppm). As the standard, ascorbic acid IC50 values were 112.0 and 101.7 ppm, respectively. GU, ChiO, and GU+ChiO at 2.5, 5.0, and 10.0 mg/mL concentrations significantly reduced Phytophthora capsici mycelial growth compared with the control treatment. GU+ChiO EC50 values were 2.04, 2.45, and 2.38 mg/mL at 3, 6, and 9 days after treatment, respectively. These results suggest that the GU and ChiO combination worked as elicitors, triggering enhanced P. capsici suppression in vitro.

Nematicidal activity of Glycyrrhiza uralensis Fisch. root extracts on Meloidogyne incognita eggs and juveniles

Dang-Minh-Chanh Nguyen,Thi-Hoan Luong,Van-Viet Nguyen,Woo-Jin Jung 한국응용생명화학회 2023 Journal of Applied Biological Chemistry (J. Appl. Vol.66 No.-

This study evaluated the in vitro nematicidal activity of Glycyrrhiza uralensis root extracts (GuRE) on Meloidogyne incognita eggs and juveniles. The results showed that treatment of M. incognita eggs with 2.0 mg/mL GuRE for 5 and 10 d resulted in 64.0 and 68.1% hatch inhibition, respectively. Furthermore, the relative mortality of J2 was 96.2% after treatment with 2.0 mg/mL GuRE for 48 h. Changes in the shape of the eggs and juveniles were determined after incubation with 2.0 mg/mL GuRE for 5 d and 48 h, respectively. These preliminary results suggest that GuRE can be used as an environment-friendly bio-nematicide to control root-knot nematodes. In the future, in vivo assays should be conducted using GuRE to ascertain its potential for widespread application as a nematicide.

Behavior of composite CFST beam-concrete column joints

Seung-Eock Kim,Ji-Hun Choi,Thai-Hoan Pham,Viet-Hung Truong,Zhengyi Kong,Nguyen-Thê Duong,Quang-Viet Vu 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.37 No.1

This paper introduces a new composite joint, which is the composite CFST beam- concrete column joint, and it is more convenient for transportation and erection than conventionally welded joints. The main components of this joint include steel H-beams welded with CFST beams, reinforced concrete columns, and reinforced concrete slabs. The steel H-beams and CFST beams are connected with a concrete slab using shear connectors to ensure composite action between them. An experimental investigation was conducted to evaluate the proposed composite joint performance. A three-dimensional (3D) finite element (FE) model was developed and analyzed for this joint using the ABAQUS/explicit. The FE model accuracy was validated by comparing its results with the relevant test results. Additionally, the parameters that consisted of the steel box beam thickness, concrete compressive strength, steel yield strength, and reinforcement ratio in the concrete slab were considered to investigate their influence on the proposed joint performance.