Nam Ha Nguyen

Prof. Nam Ha Nguyen


Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 April 2005
Verified
Conference Paper
Closed access
DKDong Seong Kim
Dong Seong Kim
NNNam Ha Nguyen
Nam Ha Nguyen
JPJong Sou Park
Jong Sou Park

29 March 2018 in Sensors
Verified
Journal Article
Open access
PDF file
DLDangNhac LU
DangNhac LU
NNNhan Nguyen
Nhan Nguyen
TNThi-Hau NGUYEN
Thi-Hau NGUYEN
NNNam Ha Nguyen
Nam Ha Nguyen
In this paper, we present a flexible combined system, namely the Vehicle mode-driving Activity Detection System (VADS), that is capable of detecting either the current vehicle mode or the current driving activity of travelers. Our proposed system is designed to be lightweight in computation and very fast in response to the changes of travelers’ vehicle modes or driving events. The vehicle mode detection module is responsible for recognizing both motorized vehicles, such as cars, buses, and motorbikes, and non-motorized ones, for instance, walking, and bikes. It relies only on accelerometer data in order to minimize the energy consumption of smartphones. By contrast, the driving activity detection module uses the data collected from the accelerometer, gyroscope, and magnetometer of a smartphone to detect various driving activities, i.e., stopping, going straight, turning left, and turning right. Furthermore, we propose a method to compute the optimized data window size and the optimized overlapping ratio for each vehicle mode and each driving event from the training datasets. The experimental results show that this strategy significantly increases the overall prediction accuracy. Additionally, numerous experiments are carried out to compare the impact of different feature sets (time domain features, frequency domain features, Hjorth features) as well as the impact of various classification algorithms (Random Forest, Naïve Bayes, Decision tree J48, K Nearest Neighbor, Support Vector Machine) contributing to the prediction accuracy. Our system achieves an average accuracy of 98.33% in detecting the vehicle modes and an average accuracy of 98.95% in recognizing the driving events of motorcyclists when using the Random Forest classifier and a feature set containing time domain features, frequency domain features, and Hjorth features. Moreover, on a public dataset of HTC company in New Taipei, Taiwan, our framework obtains the overall accuracy of 97.33% that is considerably higher than that of the state-of the art.

1 February 2019
Verified
Conference Paper
Closed access
Sang Van HaSang Van Ha
Sang Van Ha
DLDangNhac LU
DangNhac LU
GCGyoo Seok Choi
Gyoo Seok Choi
NNNam Ha Nguyen
Nam Ha Nguyen
BYByeongnam Yoon
Byeongnam Yoon

22 April 2016 in MATEC Web of Conferences
Verified
Journal Article
Open access
PDF file
Sang Van HaSang Van Ha
Sang Van Ha
NNNam Ha Nguyen
Nam Ha Nguyen
In financial risk, credit risk management is one of the most important issues in financial decision-making. Reliable credit scoring models are crucial for financial agencies to evaluate credit applications and have been widely studied in the field of machine learning and statistics. Deep learning is a powerful classification tool which is currently an active research area and successfully solves classification problems in many domains. Deep Learning provides training stability, generalization, and scalability with big data. Deep Learning is quickly becoming the algorithm of choice for the highest predictive accuracy. Feature selection is a process of selecting a subset of relevant features, which can decrease the dimensionality, reduce the running time, and improve the accuracy of classifiers. In this study, we constructed a credit scoring model based on deep learning and feature selection to evaluate the applicant's credit score from the applicant's input features. Two public datasets, Australia and German credit ones, have been used to test our method. The experimental results of the real world data showed that the proposed method results in a higher prediction rate than a baseline method for some certain datasets and also shows comparable and sometimes better performance than the feature selection methods widely used in credit scoring.

1 January 2005
Verified
Book Chapter
Closed access
PDF file
DKDong Seong Kim
Dong Seong Kim
NNNam Ha Nguyen
Nam Ha Nguyen
SOSyng-Yup Ohn
Syng-Yup Ohn
JPJong Sou Park
Jong Sou Park

13 October 2021 in BMC Bioinformatics
Verified
Journal Article
Open access
PDF file
DNDat Thanh Nguyen
Dat Thanh Nguyen
QTQuang Thinh Trac
Quang Thinh Trac
TNThi-Hau NGUYEN
Thi-Hau NGUYEN
NNNam Ha Nguyen
Nam Ha Nguyen
NONir Ohad
Nir Ohad
TVTrung Nghia Vu
Trung Nghia Vu
Background: Circular RNA (circRNA) is an emerging class of RNA molecules attracting researchers due to its potential for serving as markers for diagnosis, prognosis, or therapeutic targets of cancer, cardiovascular, and autoimmune diseases. Current methods for detection of circRNA from RNA sequencing (RNA-seq) focus mostly on improving mapping quality of reads supporting the back-splicing junction (BSJ) of a circRNA to eliminate false positives (FPs). We show that mapping information alone often cannot predict if a BSJ-supporting read is derived from a true circRNA or not, thus increasing the rate of FP circRNAs.Results: We have developed Circall, a novel circRNA detection method from RNA-seq. Circall controls the FPs using a robust multidimensional local false discovery rate method based on the length and expression of circRNAs. It is computationally highly efficient by using a quasi-mapping algorithm for fast and accurate RNA read alignments. We applied Circall on two simulated datasets and three experimental datasets of human cell-lines. The results show that Circall achieves high sensitivity and precision in the simulated data. In the experimental datasets it performs well against current leading methods. Circall is also substantially faster than the other methods, particularly for large datasets.Conclusions: With those better performances in the detection of circRNAs and in computational time, Circall facilitates the analyses of circRNAs in large numbers of samples. Circall is implemented in C++ and R, and available for use at https://www.meb.ki.se/sites/biostatwiki/circall and https://github.com/datngu/Circall.