Knowledge Discovery from the Data of Long Distance Travel Mode Choices Based on Rough Set Theory

Weijie Wang,Moon Namgung 보안공학연구지원센터 2007 International Journal of Multimedia and Ubiquitous Vol.2 No.2

The purpose of this study is to find the relationships between personal demographic attributes and long distance travel mode choices based on the Artificial Intelligence technique-rough set theory. Rough set theory can learn and refine decision rules or hidden facts from the incomplete observed data without the constraints of statistical assumptions. Also the induced decision rules are expressed in natural language, which can help policymakers in the decision making process. In the study, we conducted a survey to collect the peoples’ most preferred travel mode choices for the given destination and people’s demographic information. We analyzed the observed data based the rough set theory, calculated and discussed the approximation, core, reduct and rules of the data. The results of validation test were very promising, which showed that the induced decision rules could represent the relationships between data with the accuracy of 74.59%.

Flexible AlGaInN/GaN Heterostructures for High-Hole-Mobility Transistors

Wang, Weijie,Shervin, Shahab,Oh, Seung Kyu,Chen, Jie,Huai, Yang,Pouladi, Sara,Kim, Hyunsoo,Lee, Sung-Nam,Ryou, Jae-Hyun IEEE 2017 IEEE electron device letters Vol.38 No.8

<P>We study the potential and feasibility of high hole mobility transistors (HHMTs) based on flexible AlGaInN/GaN heterostructures using numerical simulation. We develop a map for the sheet density of two-dimensional hole gas (2DHG) at different mole fractions of AlN, GaN, and InN of AlGaInN with mechanical bending conditions. External compressive strain via bending can induce relatively high density of 2DHG (e.g.,> 8x10(12)cm(-2)) while keeping InN fraction low (<0.3) so that 2DHG channel can be formed in a GaN layer. We show the electronic energy band diagrams, family curves of I - V characteristics, and transfer characteristicsof an In-0.25 Al0.75N/GaN heterostructure in different bending conditions. By bending up, 2DHG is formed to perform the device function as HHMTs. Without bending, 2-D electron gas is induced and the devices function as high electron mobility transistors. This unique property can be used in complementary integrated circuits for high-power and high-temperature applications.</P>

Determination of the Bearing Capacity of a Concrete-filled Steel Tubular Arch Support for Tunnel Engineering: Experimental and Theoretical Studies

Weijie Zhang,Weiteng Li,Ning Yang,Qi Wang,Tingchun Li,Gang Wang 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.7

Although Concrete-filled Steel Tubular (CFST) arch support technology for transportation tunnels and mining roadways is developing rapidly, research regarding the determination of the bearing capacity of the CFST arch support is still limited. Based on a literature analysis, the definition and expression form of the bearing capacity of CFST supporting arch Qu was clarified, and determination approaches via laboratory testing and theoretical calculation methods were recommended. Full-size mechanical tests of CFST arches were performed by adhering to the suggested loading pattern that uses a number of hydraulic cylinders along the arch profile to simulate the surrounding rock pressure. The failure mode of the arches was determined as elastic-plastic instability with an extreme point. The critical criterion of global instability for the tested arch was proposed as the critical CFST section reaching the compression-bending limit. Based on the above criterion, a specific process for determining the Qu by theoretical calculation was proposed. Calculation examples show that the calculation results deviations were less than 4% compared with the tests results, and the reliability and accuracy of the new theoretical approach were thus verified. Finally, the limitations of the calculation method were noted.

A comprehensive quality analysis of randomized controlled clinical trials of Asian ginseng and American ginseng based on the CONSORT guideline

Weijie Chen,Xiuzhu Li,Zhejie Chen,Wei Hao,Peifen Yao,Meng Li,Kunmeng Liu,Hao Hu,Shengpeng Wang,Yitao Wang 고려인삼학회 2022 Journal of Ginseng Research Vol.46 No.1

Ginseng is an international herb that has been used for thousands of years. Two species most commonly applied and investigated in the ginseng family are Asian ginseng and American ginseng. The number of randomized controlled clinical trials (RCTs) has conspicuously increased, driven by the rapid development of ginseng. However, the reporting of RCT items of ginseng is deficient because of different trial designs and reporting formats, which is a challenge for researchers who are looking for the data with high quality and reliability. Thus, this study focused on providing an extensive analysis of these two species and examined the quality of the RCTs, based on the Consolidated Standards of Reporting Trials (CONSORT) guideline. Ninety-one RCTs conducted from 1980 to 2019 that were related to Asian ginseng and American ginseng used singly met our inclusion criteria. We found that the reporting quality of the two species has improved during the past 40 years. Publication date and sample size were significantly associated with the reporting quality. Rigorous RCTs designed for the species of ginseng are warranted, which can shed light on product research and development of ginseng in the future.

Controlling Ejection State of a Pneumatic Micro-droplet Generator Through Machine Vision Methods

Fei Wang,Yiwei Wang,Weijie Bao,Hui Zhang,Jiangeng Li,Zhihai Wang 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.4

Pneumatic micro-droplet ejection is a printing technique that has potential applications in many fi elds, especially in thefi eld of bio-printing. The ejection is via a solenoid valve being briefl y turned on, so that high pressure gas enters the liquidreservoir, forming a gas pressure pulse, forcing the liquid out through a tiny nozzle to form a micro-droplet. For bio-printingapplications, the bio-inks are typically non-standard. The diffi culties are not only that the initial working parameters arediffi cult to set, but also the working conditions change over time in many cases. In order to maintain a stable single-dropejection state, a machine vision based ejection monitoring was designed to obtain the number, positions and sizes of thedroplets for each ejection, and a feedback control is realized by adjusting the “ON” time of the solenoid valve or the gaspressure at the front end of the solenoid valve.

Ginsenoside Rb1 and compound K improve insulin signaling and inhibit ER stress-associated NLRP3 inflammasome activation in adipose tissue

Chen, Weijie,Wang, Junlian,Luo, Yong,Wang, Tao,Li, Xiaochun,Li, Aiyun,Li, Jia,Liu, Kang,Liu, Baolin The Korean Society of Ginseng 2016 Journal of Ginseng Research Vol.40 No.4

Background: This study was designed to investigate whether ginsenoside Rb1 (Rb1) and compound K (CK) ameliorated insulin resistance by suppressing endoplasmic reticulum (ER) stress-induced inflammation in adipose tissue. Methods: To induce ER stress, epididymal adipose tissue from mice or differentiated 3T3 adipocytes were exposed to high glucose. The effects of Rb1 and CK on reactive oxygen species production, ER stress, TXNIP/NLRP3 inflammasome activation, inflammation, insulin signaling activation, and glucose uptake were detected by western blot, emzyme-linked immunosorbent assay, or fluorometry. Results: Rb1 and CK suppressed ER stress by dephosphorylation of $IRE1{\alpha}$ and PERK, thereby reducing TXNIP-associated NLRP3 inflammasome activation in adipose tissue. As a result, Rb1 and CK inhibited IL-$1{\beta}$ maturation and downstream inflammatory factor IL-6 secretion. Inflammatory molecules induced insulin resistance by upregulating phosphorylation of insulin receptor substrate-1 at serine residues and impairing insulin PI3K/Akt signaling, leading to decreased glucose uptake by adipocytes. Rb1 and CK reversed these changes by inhibiting ER stress-induced inflammation and ameliorating insulin resistance, thereby improving the insulin IRS-1/PI3K/Akt-signaling pathway in adipose tissue. Conclusion: Rb1 and CK inhibited inflammation and improved insulin signaling in adipose tissue by suppressing ER stress-associated NLRP3 inflammation activation. These findings offered novel insight into the mechanism by which Rb1 and CK ameliorate insulin resistance in adipose tissue.

Ripplocations, kink bands and delamination cracks in carbon cathode materials

Wang Wei,Chen Weijie,Liu Haitao,Zhang Hongtao 한국탄소학회 2019 Carbon Letters Vol.29 No.4

A new deformation micromechanism operating in the carbon cathode for aluminum electrolysis termed a ripplocation has been proposed in this paper. The creep deformation of semi-graphitic cathode was measured using a modified Rapoport equipment at 965 °C with cryolite ratio = 4.0. The characteristic of the defect was obtained by analyzing TEM photograph of the carbon cathode with different testing times. The results indicated that basal dislocations, bulk ripplocations, kink bands and delamination cracks appeared in succession in the first two stages of the creep deformation. Ripplocations in the carbon cathode make a layer of carbon atoms to glide relative to each other without damaging the in-plane bonds. Ripplocations could also attract each other and result in kink boundaries. The creep strain of the carbon cathode could be accommodated by kink band and delamination cracks during aluminum electrolysis. A more comprehensive understanding of their micromechanics behaviors is very important and could deeply influence our current knowledge of the deformation mechanism of the carbon cathode for aluminum electrolysis.

Large-eddy simulation of low-swirl multi-nozzle combustion with co- and counter-swirling arrays

Weijie Liu,Bing Ge,Shusheng Zang,Huiru Wang 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1

Large-eddy simulation (LES) of CH 4 -air low-swirl flame was carried out in a multi-nozzle combustor with two burner configurations by using a premixed flamelet model. The multi-nozzle burner includes a co-swirling array where all five nozzles act in the same direction and a counter-swirling array where the center nozzle is in the opposite swirling direction to the outer nozzles. LES results are in good agreement with OH-planar laser-induced florescence data in terms of OH concentrations and combustion progress variables. Numerical results show that the flow of each nozzle is constant before merging. The neighboring flows interact with each other and generate a highvelocity zone with intensive turbulence. The kinetic energy in the interacting region for the co-swirling array is larger than that for the counter-swirling array. After neighboring flow combining, the flow develops into a unified swirling motion similar to a single swirling flow for the co-swirling array, whereas the flow maintains the individual swirling structures for the counter-swirling arrangement. However, the swirling array exerts minimal effect on multi-nozzle combustion in terms of the temperature distributions and combustion progress of premixed low-swirl multi-nozzle flames.

Laser Phase Noise to Electronic Phase Noise Conversion in Optical Links Comprising Optical Resonators

Wang, Ziye,Yang, Chun,Xu, Weijie Optical Society of Korea 2018 Current Optics and Photonics Vol.2 No.5

This article investigates the mechanism of electronic signal phase noise degradation induced by laser phase noise in optical links comprising optical resonators. Through theoretical derivation, we find that the phase noise of the output electronic signal has the same spectral shape of optical intensity noise as the output of the optical resonator. We propose that the optical resonator transfers laser phase noise to light intensity fluctuation and then the intensity fluctuation is converted to electric phase noise through AM-PM conversion mechanism in the photodiode. An optical link comprising a Fabry-Perot resonator was constructed to verify the proposed mechanism. The experimental results agree with our theoretical prediction verifying that the supposition is correct.

Ripplocations, kink bands and delamination cracks in carbon cathode materials

Wei Wang,Weijie Chen,Haitao Liu,Hongtao Zhang 한국탄소학회 2019 Carbon Letters Vol.29 No.4

A new deformation micromechanism operating in the carbon cathode for aluminum electrolysis termed a ripplocation has been proposed in this paper. The creep deformation of semi-graphitic cathode was measured using a modified Rapoport equipment at 965 °C with cryolite ratio = 4.0. The characteristic of the defect was obtained by analyzing TEM photograph of the carbon cathode with different testing times. The results indicated that basal dislocations, bulk ripplocations, kink bands and delamination cracks appeared in succession in the first two stages of the creep deformation. Ripplocations in the carbon cathode make a layer of carbon atoms to glide relative to each other without damaging the in-plane bonds. Ripplocations could also attract each other and result in kink boundaries. The creep strain of the carbon cathode could be accommodated by kink band and delamination cracks during aluminum electrolysis. A more comprehensive understanding of their micromechanics behaviors is very important and could deeply influence our current knowledge of the deformation mechanism of the carbon cathode for aluminum electrolysis.