Using algorithmic differentiation for uncertainty analysis

Water Qualit

Combination of Domain Knowledge and Deep Learning for Sentiment Analysis of Short and Informal Messages on Social Media

Sentiment analysis has been emerging recently as one of the major natural language processing (NLP) tasks in many applications. Especially, as social media channels (e.g. social networks or forums) have become significant sources for brands to observe user opinions about their products, this task is thus increasingly crucial. However, when applied with real data obtained from social media, we notice that there is a high volume of short and informal messages posted by users on those channels. This kind of data makes the existing works suffer from many difficulties to handle, especially ones using deep learning approaches. In this paper, we propose an approach to handle this problem. This work is extended from our previous work, in which we proposed to combine the typical deep learning technique of Convolutional Neural Networks with domain knowledge. The combination is used for acquiring additional training data augmentation and a more reasonable loss function. In this work, we further improve our architecture by various substantial enhancements, including negation-based data augmentation, transfer learning for word embeddings, the combination of word-level embeddings and character-level embeddings, and using multitask learning technique for attaching domain knowledge rules in the learning process. Those enhancements, specifically aiming to handle short and informal messages, help us to enjoy significant improvement in performance once experimenting on real datasets.Comment: A Preprint of an article accepted for publication by Inderscience in IJCVR on September 201

Improved solvent extraction procedure and HPLC-ELSD method for analysis of polar lipids from dairy materials

A normal phase HPLC-ELSD method which was improved from the method of Rombaut et al. 2005 (J. Dairy Sci. 88(2):482-488) for analysis of polar lipids (PLs) is presented. In the improved method, the mobile phase consisted of two lines; dichloromethane and a mixture of methanol and acetic acid/triethylamine buffer. Dichloromethane is less toxic than chloroform which was used in the old method. PLs of interest such as glycolipids, phospholipids and sphingomyelin were well separated with a total time for one analysis run of 22.5 min. Peak retention times and peak area were reproducible due to a good miscibility of mobile phases. The improved HPLC-ELSD method was applicable for both PLs from soy lecithin and dairy materials. Furthermore, a modified solvent extraction method of PLs from dairy matrices was adapted. The modified method offered higher extraction efficiency, consumed less time and in some cases saved solvent use

Design a cryptosystem using elliptic curves cryptography and Vigenère symmetry key

In this paper describes the basic idea of elliptic curve cryptography (ECC) as well as Vigenère symmetry key. Elliptic curve arithmetic can be used to develop elliptic curve coding schemes, including key exchange, encryption, and digital signature. The main attraction of elliptic curve cryptography compared to Rivest, Shamir, Adleman (RSA) is that it provides equivalent security for a smaller key size, which reduces processing costs. From the theorical basic, we proposed a cryptosystem using elliptic curves and Vigenère cryptography. We proposed and implemented our encryption algorithm in an integrated development environment named visual studio 2019 to design a safe, secure, and effective cryptosystem

An identification of the tolerable time-interleaved analog-to-digital converter timing mismatch level in high-speed orthogonal frequency division multiplexing systems

High-speed Terahertz communication systems has recently employed orthogonal frequency division multiplexing approach as it provides high spectral efficiency and avoids inter-symbol interference caused by dispersive channels. Such high-speed systems require extremely high-sampling time-interleaved analog-to-digital converters at the receiver. However, timing mismatch of time-interleaved analog-to-digital converters significantly causes system performance degradation. In this paper, to avoid such performance degradation induced by timing mismatch, we theoretically determine maximum tolerable mismatch levels for orthogonal frequency division multiplexing communication systems. To obtain these levels, we first propose an analytical method to derive the bit error rate formula for quadrature and pulse amplitude modulations in Rayleigh fading channels, assuming binary reflected gray code (BRGC) mapping. Further, from the derived bit error rate (BER) expressions, we reveal a threshold of timing mismatch level for which error floors produced by the mismatch will be smaller than a given BER. Simulation results demonstrate that if we preserve mismatch level smaller than 25% of this obtained threshold, the BER performance degradation is smaller than 0.5 dB as compared to the case without timing mismatch

KỸ THUẬT TÁCH BA ĐỈNH CHẬP TRONG PHỔ BỨC XẠ GAMMA

Separating the three overlapped peaks of a Gamma spectrum is essential requirements in experimental nuclear physics as well as in analysis of gamma-ray spectrum. In this paper, we present the results of calculations for the problem of overlap peaks, in which three individual peaks are overlapped with each other. The calculation procedure was performed by the Levenberg-Marquardt algorithm with linear and nonlinear background. Based on separating the two overlap peaks method has been implemented in our previous article, the separating three overlap peaks was successfully implemented in this paper, in which the calculations were tested with gamma-ray spectra by using a Semiconductor detector and a Scintillator detector.Trong quá trình xử lý phổ bức xạ, vấn đề tách hai hay ba đỉnh chập trong phân tích đỉnh phổ năng lượng bức xạ Gamma là thường gặp. Kỹ thuật tách hai đỉnh chập đã được công bố trong các kết quả nghiên cứu của Mai và Võ (2015). Trong bài báo này chúng tôi trình bày kỹ thuật tách ba đỉnh chập bằng thuật toán Levenberg- Marquardt với nền phông tuyến tính hoặc phi tuyến. Thuật toán đã được áp dụng thành công trên các phổ bức xạ đo từ detector nhấp nháy hay bán dẫn