Autonomous Alert Generation and Recommendation for Disaster Management

Yuxuan Zhao,Ka Lok Man 한국재활복지공학회 2017 한국재활복지공학회 학술대회논문집 Vol.2017 No.11

Fabrication, Microstructure and Compression Properties of AZ31 Mg Foams

Zhao, Rui,Li, Yuxuan,Jeong, Seung-Reuag,Yue, Xuezheng,Hur, Bo-Young Materials Research Society of Korea 2011 한국재료학회지 Vol.21 No.6

Melt foaming method is one of cost-effective methods to make metal foam and it has been successfully applied to fabricate Mg foams. In this research, AZ31 Mg alloy ingot was used as a metal matrix, using AlCa granular as thickening agent and $CaCO_3$ powder as foaming agent, AZ31 Mg alloy foams were fabricated by melt-foaming method at different foaming temperatures. The porosity was above 41.2%~73.3%, pore size was between 0.38~1.52 mm, and homogenous pore structures were obtained. Microstructure and mechanical properties of the AZ31 Mg alloy foams were investigated by optical microscopy, SEM and UTM. The results showed that pore structure and pore distribution were much better than those fabricated at lower temperatures. The compression behavior of the AZ31 Mg alloy foam behaved as typical porous materials. As the foaming temperature increased from $660^{\circ}C$ to $750^{\circ}C$, the compressed strength also increased. The AZ31 Mg alloy foam with a foaming temperature of $720^{\circ}C$ had the best energy absorption. The energy absorption value of Mg foam was 15.52 $MJ/m^3$ at a densification strain of 52%. Furthermore, the high energy absorption efficiencies of the AZ31 Mg alloy foam kept at about 0.85 in the plastic plateau region, which indicates that composite foam possess a high energy absorption characteristic, and the Vickers hardness of AZ31 Mg alloy foam decreased as the foaming temperature increased.

An Enhanced Video Anomaly Detection System for Smart City Management

Yuechun Wang,Shufei Zhu,Yuxuan Zhao,Jie Zhang,Ka Lok Man 한국ITS학회 2022 한국ITS학회 학술대회 Vol.2022 No.06

Since the popularity of city monitoring systems has increased, surveillance videos have become more common. However, due to the massive increment of social event needs after lifting the coronavirus pandemic lockdown, the pressure of handling anomalies on government departments is growing with each passing day. In addition, surveillance cameras cannot record every corner of our city. There are still blind areas such as indoor environments and remote regions. Therefore, this paper introduces and develops an comprehensive system for video anomaly detection in smart city management, which is based on mobile phones, to enlarge the coverage of the current surveillance system. This system can capture and transmit abnormal videos. In addition, a deep learning method (VGG16) is implemented in the system to do video anomaly detection.

Selective absorption of H2S and CO2 from simulated coke oven gas by aqueous blends of N-methyldiethanolamine and tetramethylammonium glycine

Pan Zhang,Yuetong Zhao,Xiangfeng Tian,Yanxi Ji,Yuxuan Shu,Kun Fu,Dong Fu,Lemeng Wang 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.11

Tetramethylammonium glycine ([N1111][Gly]) can be completely ionized into cation [N1111]+ and anion [Gly] in aqueous solution. The anion contains an amino -NH2 and a carboxyl -COO, both of which can react with hydrogen sulfide (H2S). Therefore, [N1111][Gly] was used to promote the selective absorption of H2S in coke oven gas (COG) by N-methyldiethanolamine (MDEA). The absorption performance and selectivity of H2S in the aqueous solution of MDEA-[N1111][Gly] were investigated. The effects of MDEA mass fraction, [N1111][Gly] mass fraction, temperature, H2S partial pressure and CO2 partial pressure on the absorption capacity and selectivity were clarified. The results showed that an aqueous solution of MDEA-[N1111][Gly] has good selectivity for H2S in COG. The absorption capacity was large and the mass fraction of the solute in the absorbent reached more than 0.55, thereby having outstanding advantages in the aspects of saving energy consumption and operating cost and having a good application potential.

Enhancing Diabetes Prediction Using Advanced Machine Learning Techniques

James Muljana,Xianbin Hong,Jie Zhang,Yuxuan Zhao,Yuechun Wang,Vijayakumar Nanjappan,Kalok Man 한국디지털콘텐츠학회 2023 The Journal of Contents Computing Vol.5 No.2

Diabetes has been an issue over the past few decades, where it keeps on having an upward trend throughout each year. One of the biggest contributing factor is caused by the possibility that people can remain undiagnosed during their early stages of diabetes. Therefore, this research is done to help develop a machine learning good enough to diagnose early-stage diabetes. The development of this machine learning will use the Pima Indian Diabetes Dataset, since another dataset is unable to be obtained. The methods to achieve a great model for identifying diabetes will be divided to 5 parts which are data preparation, exploratory data analysis, feature engineering, build the model, and evaluate it. There are various kinds of techniques on finishing each steps mentioned that are tried, however only some techniques support the model well.

Water-blocking Asphyxia of N95 Medical Respirator During Hot Environment Work Tasks With Whole-body Enclosed Anti-bioaerosol Suit

Zhu Jintuo,Jiang Qijun,Ye Yuxuan,He Xinjian,Shao Jiang,Li Xinyu,Zhao Xijie,Xu Huan,Hu Qi 한국산업안전보건공단 산업안전보건연구원 2023 Safety and health at work Vol.14 No.4

Background: During hot environment work tasks with whole-body enclosed anti-bioaerosol suit, the combined effect of heavy sweating and exhaled hot humid air may cause the N95 medical respirator to saturate with water/sweat (i.e., water-blocking). Methods: 32 young male subjects with different body mass indexes (BMI) in whole-body protection (N95 medical respirator + one-piece protective suit + head covering + protective face screen + gloves + shoe covers) were asked to simulate waste collecting from each isolated room in a seven-story building at 27-28°C, and the weight, inhalation resistance (Rf), and aerosol penetration of the respirator before worn and after water-blocking were analyzed. Results: All subjects reported water-blocking asphyxia of the N95 respirators within 36-67 min of the task. When water-blocking occurred, the Rf and 10-200 nm total aerosol penetration (Pt) of the respirators reached up to 1270-1810 Pa and 17.3-23.3%, respectively, which were 10 and 8 times of that before wearing. The most penetration particle size of the respirators increased from 49-65 nm before worn to 115-154 nm under water-blocking condition, and the corresponding maximum size-dependent aerosol penetration increased from 2.5-3.5% to 20-27%. With the increase of BMI, the water-blocking occurrence time firstly increased then reduced, while the Rf, Pt, and absorbed water all increased significantly. Conclusions: This study reveals respirator water-blocking and its serious negative impacts on respiratory protection. When performing moderate-to-high-load tasks with whole-body protection in a hot environment, it is recommended that respirator be replaced with a new one at least every hour to avoid water-blocking asphyxia.

Synthesis and Cytotoxicity Evaluation of New 3-substituted 4-(4-methyloxy phenyl)-1H-Pyrrole Derivatives

Xiaoping Zhan,Lan Lan,Yuankui Zhang,Jian Chen,Kai Zhao,Shuai Wang,Yuxuan Xin,Zhenmin Mao 대한화학회 2016 Bulletin of the Korean Chemical Society Vol.37 No.2

A new series of 3-substituted 4-(4-methyloxy phenyl)-1H-pyrrole derivatives were synthesized and biologically evaluated for potential anticancer activity. Fifteen targeted compounds showed high selectivity toward normal cells and cancer cells: that is, all targeted compounds had no obvious cytotoxicity toward normal human cells (HUVEC and NIH/3T3), but some compounds exhibited broad-spectrum proliferation inhibitory activity against the screened cancer cell lines. Among these pyrrole derivatives, compounds 3b and 3o showed potent anticancer activity against the MG-63 cell line, with IC50 values of 14.9 and 12.7 μM, respectively. Other pyrrole derivatives also showed promising proliferation inhibitory activity, including compound 3d against A375 (IC50 = 18.6 μM), compound 3f and 3j against MGC80-3 (IC50 = 19.9 μM), and compound 3o against MGC80-3 (IC50 = 11.9 μM). Because the developed pyrrole derivatives showed strong anticancer activity and high selectivity, this new series of pyrrole derivatives could be considered as promising lead compounds for further development of potent and safe anticancer agents.