보존 경계 사각형을 이용한 이동객체의 현재와 미래 위치 색인

황도퉁(Hoang Do Thanh Tung),정영진(Young-Jin Jung),이응재(Eung-Jae Lee),류근호(Keun-Ho Ryu) 한국정보과학회 2003 한국정보과학회 학술발표논문집 Vol.30 No.2Ⅱ

Nowadays, with numerous emerging applications (e.g., traffic control, meteorology monitoring, mobile computing, etc.), access methods to process current and future queries for moving objects are becoming increasingly important. Among these methods, the time-parameterized R-tree (TPR-tree) seems likely the most flexible method in one, two, or three-dimensional space. A key point of TPR-tree is that the (conservative) bounding rectangles are expressed by functions of time. In this paper, we propose a new method, which takes into account positions of its moving objects against the rectangle's bounds. In proposed method, the size of bounding rectangle is significantly smaller than the traditional bounding rectangle in many cases. By this approach, we believe that the TPR-tree can improve query performance considerably.

Metagenomic analysis of bacterial community structure and diversity of lignocellulolytic bacteria in Vietnamese native goat rumen

Do, Thi Huyen,Dao, Trong Khoa,Nguyen, Khanh Hoang Viet,Le, Ngoc Giang,Nguyen, Thi Mai Phuong,Le, Tung Lam,Phung, Thu Nguyet,Straalen, Nico M. van,Roelofs, Dick,Truong, Nam Hai Asian Australasian Association of Animal Productio 2018 Animal Bioscience Vol.31 No.5

Objective: In a previous study, analysis of Illumina sequenced metagenomic DNA data of bacteria in Vietnamese goats' rumen showed a high diversity of putative lignocellulolytic genes. In this study, taxonomy speculation of microbial community and lignocellulolytic bacteria population in the rumen was conducted to elucidate a role of bacterial structure for effective degradation of plant materials. Methods: The metagenomic data had been subjected into Basic Local Alignment Search Tool (BLASTX) algorithm and the National Center for Biotechnology Information non-redundant sequence database. Here the BLASTX hits were further processed by the Metagenome Analyzer program to statistically analyze the abundance of taxa. Results: Microbial community in the rumen is defined by dominance of Bacteroidetes compared to Firmicutes. The ratio of Firmicutes versus Bacteroidetes was 0.36:1. An abundance of Synergistetes was uniquely identified in the goat microbiome may be formed by host genotype. With regard to bacterial lignocellulose degraders, the ratio of lignocellulolytic genes affiliated with Firmicutes compared to the genes linked to Bacteroidetes was 0.11:1, in which the genes encoding putative hemicellulases, carbohydrate esterases, polysaccharide lyases originated from Bacteroidetes were 14 to 20 times higher than from Firmicutes. Firmicutes seem to possess more cellulose hydrolysis capacity showing a Firmicutes/Bacteroidetes ratio of 0.35:1. Analysis of lignocellulolytic potential degraders shows that four species belonged to Bacteroidetes phylum, while two species belonged to Firmicutes phylum harbouring at least 12 different catalytic domains for all lignocellulose pretreatment, cellulose, as well as hemicellulose saccharification. Conclusion: Based on these findings, we speculate that increasing the members of Bacteroidetes to keep a low ratio of Firmicutes versus Bacteroidetes in goat rumen has resulted most likely in an increased lignocellulose digestion.

FGW-FER: Lightweight Facial Expression Recognition with Attention

Huy-Hoang Dinh,Hong-Quan Do,Trung-Tung Doan,Cuong Le,Ngo Xuan Bach,Tu Minh Phuong,Viet-Vu Vu 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.9

The field of facial expression recognition (FER) has been actively researched to improve human-computer interaction. In recent years, deep learning techniques have gained popularity for addressing FER, with numerous studies proposing end-to-end frameworks that stack or widen significant convolutional neural network layers. While this has led to improved performance, it has also resulted in larger model sizes and longer inference times. To overcome this challenge, our work introduces a novel lightweight model architecture. The architecture incorporates three key factors: Depth-wise Separable Convolution, Residual Block, and Attention Modules. By doing so, we aim to strike a balance between model size, inference speed, and accuracy in FER tasks. Through extensive experimentation on popular benchmark FER datasets, our proposed method has demonstrated promising results. Notably, it stands out due to its substantial reduction in parameter count and faster inference time, while maintaining accuracy levels comparable to other lightweight models discussed in the existing literature.

Cadmium selenium nanocrystal: first-principles insight into the structural, electronic, and optical properties

Thi Le Anh,Tan Man Minh,Tung Do Hoang,Tam Do Quang,Hoa Nguyen Minh 한국물리학회 2022 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.80 No.9

A first-principles calculation has investigated the structural, electronic, optical of the CdSe nanocrystal (NC) based on the generalized gradient approximation (GGA) method within the density functional theory. The geometric optimization of the unit cell is in good agreement with our experimental data. The band structure, density of states of the NC were analyzed. The results found that CdSe NC is a direct bandgap with an estimated 1.48 eV. We also report the results of dielectric functions and the refractive index (n) characterized. It is indicated that CdSe materials have excellent photoelectric properties potential applications in optoelectronic devices.

Numerical Analysis of Dielectrophoresis-Based Microfluidic Chip with a Facing-Electrode Design for Cell Separation

Nguyen Thu Hang,Nguyen Mai Chi,Nguyen Hoang Trung,Thi Y Van Tran,Vu Ngoc Trung,Thu Hang Bui,Duc Trinh Chu,Bui Tung Thanh,Jen Chun-Ping,Quang Loc Do 한국농업기계학회 2024 바이오시스템공학 Vol.49 No.1

Purpose Circulating tumor cell separation and analysis have played a critical role in cancer diagnosis, prognosis, and treatment. In this work, we aim to design and investigate a novel biochip that integrates dielectrophoresis, microfl uidic technology to separate circulating tumor cells from blood cells. To create a dielectrophoresis-induced non-uniform electric fi eld, a facing-electrode design was proposed and utilized, in which a slanted electrode array and a simple rectangular ground electrode are placed parallel on the top and bottom parts of the microfl uidic channel, respectively. This design can reduce the particle position dependence in the microchannel and the complexity of the microfabrication process. Methods The separation process, effi ciency, and optimization of the proposed device were numerically investigated using the fi nite element method. Parametric research was conducted to comprehensively examine the impact of various operating and design factors on the cell movement and trajectories in the microfl uidic device. Results The results indicated the potential of the proposed biochip to ensure cancer cell separation from blood cells with high effi ciency, high purity in a label-free, non-invasive, easy integration, and low-cost manner. Under the optimal conditions, the separation effi ciency reached 92%, 88%, and 96% for human colon cancer cells (HT-29), red blood cells, and white blood cells, respectively. Conclusions In this study, a novel DEP-based microfl uidic chip was proposed to separate HT-29 tumor cells from blood cells and numerically investigated to verify the performance of the biochip design. Our fi ndings could provide a foundation for further theoretical and practical investigations. The proposed system can separate cancer cells from red blood cells and white blood cells as well as off ers numerous advantages, such as compact size, low voltage, high effi ciency, non-invasiveness, and label-free nature. The tumor cell enrichment platform has the potential for application in cancer detection, analysis, and assessment.

An online Indigenous Knowledge Database on Climate Change Adaptation of Farmers in the Vietnam Mekong Delta

Van Hoa Nguyen,Thi Mai Phung Bui,Thanh Phong Le,Hoang Tung Nguyen,Minh Tuyen Truong,Minh Nhut Do,Van Nha Duong 인간식물환경학회 2022 인간식물환경학회지 Vol.25 No.6

Background and objective: For countries vulnerable to climate change as Vietnam, indigenous knowledge (IK) might assist in revealing the values of local people's adaptations to environmental stresses and potentially support decision-making. Despite IK can provide the adaptive capacity of local people's activities within environmental contexts, but it is rapidly vanishing. This study aimed to describe the documentation of IK associated with climate change adaptation of farmers in the Vietnam Mekong Delta (VMD). Methods: We focused on collecting and establishing online access to IK documents through collaboration between IK holders, public sector, collecting institutions, and researchers in the five agro-ecological zones of the VMD. An online IK database for storing IK documents has been designed and implemented based on the web application schema. Results: Through interviews, we gathered IK from farming practices that are well-adapted to climate risks such as floods, droughts, and saltwater intrusions as well as traditional knowledge being used to forecast weather, flood, and saltwater intrusion. The database for storing IK documents has been successfully deployed using free and open-source software. The database currently contains more than 260 IK documents, with their location on agro-ecological zones displayed on a web-based map. Conclusion: We have captured and provided an online access to IK on climate change adaptation of the farmers in the VMD. This research is expected as an initial strategy for long-term sustainable development of the agriculture system in this region.