Learning Pattern Classification Tasks with Imbalanced Data Sets

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HyperPubSub: Blockchain based Publish/Subscribe

In this paper we describe the architecture and the implementation of a broker based publish/subscribe system where the broker role is played by a private blockchain, Hy-perledger Fabric. We show the effectiveness of our architecture by implementing and deploying a photo trading plateform. Interestingly, our architecture is generic enough to be adapted to any digital asset trading

Ecpoc: an evolutionary computation-based proof of criteria consensus protocol

Recently, blockchain technology has been applied in many domains in our life. Blockchain networks typically utilize a consensus protocol to achieve consistency among network nodes in a decentralized environment. Delegated Proof of Stake (DPoS) is a popular mechanism adopted in many networks such as BitShares, EOS, and Cardano because of its speed and scalability advantages. However, votes that come from nodes on a DPoS network tend to support a set of specific nodes that have a greater chance of becoming block producers after voting rounds. Therefore, only a small group of nodes can be selected to become block producers. To address this issue, we propose a new protocol called Evolutionary Computation-based Proof of Criteria (ECPoC), which uses ten criteria to evaluate and select a new block procedure in each round. Next, a set of optimal weights used for maximizing the network’s decentralization level is identified through the use of evolutionary computation algorithms. The experimental results show that our consensus significantly enhances the degree of decentralization in the selection process of witness nodes compared to DPoS. As a result, ECPoC facilitates fairness between nodes and creates momentum for blockchain network developmen

All-dielectric Metamaterial for Electromagnetically-induced Transparency in Optical Region

Metamaterial (MM) is emerging as a promising approach to manipulate electromagnetic waves, spanning from radio frequency to the optical region. In this paper, we employ an effect called electromagnetically-induced transparency (EIT) in all-dielectric MM structures to create a narrow transparent window in opaque broadband of the optical region (580-670 nm). Using dielectric materials instead of metals can mitigate the large non-radiative ohmic loss on the metal surface. The unit-cell of MM consists of Silicon (Si) bars on Silicon dioxide (SiO$_{2}$) substrate, in which two bars are directed horizontally and one bar is directed vertically. By changing the relative position and dimension of the Si bars, the EIT effect could be achieved. The optical properties of the proposed MM are investigated numerically using the finite difference method with commercial software Computer Simulation Technology (CST). Then, characteristic parameters of MM exhibiting EIT effect (EIT-MM), including Q-factor, group delay, are calculated to evaluate the applicability of EIT-MM to sensing and light confinement

Effect of Polypyrrole on the Electrical, Dielectric and Mechanical Properties of Waterborne Epoxy Coatings

In this context, conducting composite based on waterborne epoxy system and polypyrrole (PPy) was investigated. The polypyrrole was synthesized by chemical oxidation polymerization. Its morphology and chemical structure were confirmed by using field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). Then, PPy was well-dispersed in the epoxy coating and had a good compatibility with the matrix. The effects of PPy on dielectric, electrical and mechanical properties of epoxy/PPy composites was examined. The dielectric constant and electrical conductivity of the coatings increased with addition of PPy fillers. Over to 15 wt. % of PPy loading, the volume resistivity of samples slightly decreased from 6.7 × 1010 to 1.5 × 1010 Ω cm. In contrast, the presence of PPy diminished both impact and abrasion resistance of the epoxy/PPy composites, down to 160 kg cm and 10.2 L/mil, respectively, but they stayed acceptable for the coatings. The results reveal that the epoxy containing polypyrrole is suitable for various electrical and dielectric applications

ẢNH HƯỞNG CỦA ASTAXANTHIN BỔ SUNG TRONG THỨC ĂN LÊN TĂNG TRƯỞNG, TỶ LỆ SỐNG VÀ MÀU SẮC DA CÁ KHOANG CỔ NEMO, Amphiprion ocellaris THƯƠNG MẠI

This study examined the influence of astaxanthin added to food on growth, survival rate and pigmentation of commercial false clownfish, Amphiprion ocellaris. Five experiments were performed with synthetic astaxanthin contents: 0; 50; 100; 150 and 200 mg/kg diets. Mean weight and mean length of fish were 1.16 ± 0.22 gand and 33.05 ± 3.29 mm respectively. Fish were fed by 5% of their live weight during the examination of 8 weeks. After 56 days of experiments, the skin pigmentation levels were analysed using Clownfish Exercise pigmentation chart which has a scale from 1 to 10. Color scales of 5 experiments: 0; 50; 100; 150 and 200 mg Astaxanthin/kg diets were 2.12 ± 0.08, 3.79 ± 0.1, 5.31 ± 0.14, 7.78 ± 0.09, 8.04 ± 0.12 respectively. The result showed that the dietary astaxanthin could increase coloration of skin compared with the control group which had the lightest color (P 0.05) but there were no significant effects on growth and survival rate of clownfish (P 0.05).Nghiên cứu này đánh giá ảnh hưởng của Astaxanthin bổ sung trong thức ăn lên tăng trưởng, tỷ lệ sống và màu sắc da của cá khoang cổ Nemo Amphiprion ocellaris thương mại. Năm lô thí nghiệm được thực hiện với hàm lượng astaxanthin tổng hợp (Carophyll Pink 10% CWS) bổ sung vào trong thức ăn là: 0, 50, 100, 150 và 200 mg/kg. Cá thí nghiệm có khối lượng và chiều dài trung bình ban đầu tương ứng là 1,16 ± 0,22 g và 33,05 ± 3,29 mm. Cá được cho ăn với khẩu phần 5% khối lượng thân trong 8 tuần. Sau 56 ngày nuôi màu sắc da của cá được đánh giá bằng phương pháp cho điểm sử dụng thước so màu Clownfish Exercise có thang điểm từ 1 tới 10. Thang điểm màu sắc của 5 lô bổ sung 0, 50, 100, 150 và 200 mg Astaxanthin/kg thức ăn lần lượt là: 2,12 ± 0,08; 3,79 ± 0,1; 5,31 ± 0,14; 7,78 ± 0,09; 8,04 ± 0,12. Kết quả cho thấy những lô thí nghệm có bổ sung Astaxanthin làm tăng màu sắc da của cá so với lô đối chứng (P0,05) nhưng không có sự khác biệt có ý nghĩa về tăng trưởng và tỷ lệ sống giữa các lô thí nghiệm với nhau (P 0,05)