Utilization of Completely Recycled Fine Aggregate for Preparation of Lightweight Concrete Partition Panels

Yibo Yang,Baixi Chen,Weizhen Zeng,Yanjun Li,Qiaohui Chen,Wenying Guo,Hengchang Wang,Yingqin Chen 한국콘크리트학회 2021 International Journal of Concrete Structures and M Vol.15 No.5

To reduce the cost of lightweight concrete (LWC) partition panels and to address recycling concrete waste, this work utilized completely recycled fine aggregate (CRFA) to replace the natural fine aggregate and ceramsite in the preparation of LWC and LWC partition panels. To this end, an autoclave-free curing process and an air-entraining agent were used to prepare the CRFA-LWC. The workability, compressive strength, drying shrinkage, and pore structure of the CRFA-LWC and the performance of the CRFA-LWC partition panels were then investigated. The results show that the optimal ratio of the CRFA to the cement is 2.2 for the lightweight concrete, and the optimal panel cross section is a rounded rectangular one. All the pores in the CRFA-LWC have a diameter of smaller than 0.17 mm, and the diameter of 89% of them is less than 0.05 mm. In order to satisfy the drying shrinkage requirements stipulated by Chinese code JC/T 169-2016, the CRFA-LWC should be cured for at least 10 days. The economic analysis concludes that the material cost of CRFA-LWC is 40% lower than that of the autoclaved ceramsite concrete. In addition, utilizing CRFA in lightweight concrete can ease the shortage of natural aggregate.

On-Line Prediction of Impulse Spark and Arc Discharge Removals of Metal Bond in Dry Electrical Discharge Dressing of Diamond Grinding Wheel

Yanjun Lu,Jiajing Sun,Xiaoyu Wu,Fumin Chen 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.10 No.2

The electrical discharge is able to realize efficient dressing for metal-bonded diamond wheel, but the monitoring and prediction of dressing status have been technical bottleneck in industrialization. Hence, the metal bond removal model of impulse spark and arc discharges is proposed to realize on-line monitoring and prediction for micro grain protrusion on diamond grinding wheel surface. The relationship between microremovals of metal bond and impulse spark and arc discharge parameters was investigated for controllable dressing. First, the static and dynamic impulse discharge experiments were carried out to reveal metal bond removal mechanisms of impulse spark and arc discharges; then the relationship between characterized impulse discharge parameters and removal of metal bond was quantitatively analyzed; finally, the dry electro-contact discharge (ECD) dressed coarse diamond wheels were applied to perform smooth surface and mirror grinding of optical glass and mold steels against mechanical dressed wheels. It is found that the critical transition value of arc discharge to spark discharge under static discharge and dynamic discharge conditions were 0.059 and 0.038, respectively. In comparison with mechanical dressing, the dry ECD can obtain higher grain protrusion height to improve ground surface quality, leading to a microscopic smooth surface of BAK3 optical glass and macroscopic mirror-like surface of model steels. It is confirmed that the established relationship model can be effectively used to on-line predict the removal of metal bond with the average prediction error of 10.1% and microscopic grain protrusion by characterized impulse discharge parameters.

Methylation of methyltrichlorosilane with methyl chloride over active metals and activated carbon

Yanjun Liu,Yiqian Jiang,Weiguang Chen,Yutang Shen,Yonghai Feng,Lingqin Shen,Aili Wang,Tingshun Jiang,Zhanao Wu 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.12

Gas phase methylation of methyltrichlorosilane with methyl chloride to high-valued dimethyldichlorosilane was carried out by using metallic aluminum as a chlorine acceptor in the co-presence of activated carbon, tin, and zinc. The addition of activated carbon in metallic aluminum significantly enhanced the methylation of methyltrichlorosilane,and dimethyldichlorosilane was dominantly produced. Activated carbon played a catalyst role in the methylation reaction. When active metals, such as tin and zinc, were added in the mixture of aluminum and activated carbon,the active metals and activated carbon synergistically catalyzed the methylation of methyltrichlorosilane with methyl chloride toward the formation of dimethyldichlorosilane.

Impedance Coordinative Control for Cascaded Converter in Bidirectional Application

Yanjun Tian,Fujin Deng,Zhe Chen,Xiaofeng Sun,Yanting Hu 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Two stage cascaded converters are widely used in bidirectional applications, but the negative impedance may cause system instability. Actually the impedance interaction is much different between forward power flow and reversed power flow, which will introduce more uncertainty to the system stability. This paper proposes a control method for the constant power controlled converter in cascaded system, and consequently it can change the negative impedance of constant power converter into resistive impedance, which will improve the cascaded system stability, as well as merge the impedance difference between forward and reversed power flow. This paper addresses the analysis with the topology of cascaded dualactive - bridge converter (DAB) with inverter, and the proposed control method can also be implemented in unidirectional applications and other general cascaded converter system. The effectiveness has been validated by both simulation and experimental results.

Impedance Interaction Modeling and Analysis for Bidirectional Cascaded Converters

Yanjun Tian,Fujin Deng,Zhe Chen,Xiaofeng Sun,Yanting Hu 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

For the cascaded converter system, the output impedance of source converter interacts with the input impedance of load converter, and the interaction may cause the system instability. In bidirectional applications, when the power flow is reversed, the impedance interaction also varies, which brings more uncertainty to the system stability. An investigation is performed here for showing that the forward and reverse interactions are prominently different in terms of dynamics and stability even though the cascaded converter control remains unchanged. An important guideline has been drawn for the control of the cascaded converter. That is when voltage mode converter working as the load converter; the constant power mode converter as the source converter, the system is more stable. The concluded findings have been verified by simulation and experimental results.

A Fast and Secure Scheme for Data Outsourcing in the Cloud

( Yanjun Liu ),( Hsiao-ling Wu ),( Chin-chen Chang ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.8

Data outsourcing in the cloud (DOC) is a promising solution for data management at the present time, but it could result in the disclosure of outsourced data to unauthorized users. Therefore, protecting the confidentiality of such data has become a very challenging issue. The conventional way to achieve data confidentiality is to encrypt the data via asymmetric or symmetric encryptions before outsourcing. However, this is computationally inefficient because encryption/decryption operations are time-consuming. In recent years, a few DOC schemes based on secret sharing have emerged due to their low computational complexity. However, Dautrich and Ravishankar pointed out that most of them are insecure against certain kinds of collusion attacks. In this paper, we proposed a novel DOC scheme based on Shamir`s secret sharing to overcome the security issues of these schemes. Our scheme can allow an authorized data user to recover all data files in a specified subset at once rather than one file at a time as required by other schemes that are based on secret sharing. Our thorough analyses showed that our proposed scheme is secure and that its performance is satisfactory.

Molecular Epidemiology and Prevalence of Echovirus 30 in Zhejiang Province, China, from 2002 to 2015

( Yin Chen ),( Yi Sun ),( Juying Yan ),( Ziping Miao ),( Changping Xu ),( Yanjun Zhang ),( Haiyan Mao ),( Liming Gong ) 한국미생물생명공학회(구 한국산업미생물학회) 2017 Journal of microbiology and biotechnology Vol.27 No.12

Echovirus serotype 30 (ECHO30) has been responsible for several recent worldwide outbreaks of viral meningitis. In Zhejiang Province, China, ECHO30 has been one of the main causes of viral meningitis for years. This study, using phylogenetic analysis of the VP1 gene, was performed to investigate the general molecular epidemiology and genetic patterns of ECHO30 circulating in Zhejiang Province between the years 2002 and 2015. The nucleotide sequences of ECHO30 VP1 showed that they were 64.8% identical with the prototype strain, Bastianni, while the amino acids were 84.9% identical. Phylogenetic analyses showed that ECHO30 in the Zhejiang area has diverged into two genotypes. Genotype I consists of strains isolated since 2002, whereas genotype II includes strains that were mainly isolated during the 2002 to 2004 outbreak. ECHO30 has been endemically circulating in both humans and the environment for a long period of time. Additionally, we evaluated the significance of recombination presented during the years 2005 to 2007 to demonstrate that recombination plays an important role in the prevalence of ECHO30 in the Zhejiang area.

현대 음악산업에서의 민족음악 보존에 관한 고찰- 여자 12악방의 활동연혁 및 음악 분석을 중심으로 -

진곤(Chen Kun),메이유(Li Meiyu),최안군(Cui Yanjun),양몽도(Yang Mengtao),류은주(Eunjoo Ryu) 문학과언어연구회 2018 문화와 융합 Vol.40 No.3

중국 전통음악은 민족 문화의 중요한 구성 부분이다. 전통음악의 태동부터 현재까지 몇 천 년의 역사를 거쳐 발전해 왔다. 중국 음악 발전에서 우수한 민족음악 작품들이 매우 중요한 위치를 차지하고 있었다. 그러나 개혁 개방 이후 록 음악과 팝 음악이 신속한 속도로 발전하면서 전통 민족음악의 위치가 흔들리게 되었다. 본 연구에서는 최근 중국과 일본을 중심으로 선풍적 인기를 끌었던 민족음악그룹 여자 12악방을 중심으로 민족음악이 대중성을 확보하는 데 있어 가능성과 문제점을 고찰하고자 하였다. 따라서 그들이 인기를 끌었던 2009년 이전과 주목을 받지 못하고 하향세에 돌입하였던 시기를 부상시대와 추락시대로 나누어 대표곡을 선정하였으며, 이를 분석하여 그 음악적 특징을 파악하고, 그들의 인기가 상승했던 이유와 하락한 이유를 분석하였다. 나아가 민족음악이 대중화되고, 음악산업에서 지속적으로 대중에게 사랑을 받기 위해서 다양한 매력과 민족음악의 제작과 홍보 전략을 통해 민족음악을 보존할 수 있는 방안을 제시함으로써 민족 문화를 선양하는데 기여하기를 바라는 바이다. Chinese traditional music is an important part of national culture. It has evolved through the history of thousands of years since the birth of traditional music. In the development of Chinese music, excellent ethnic music works occupied a very important position. However, the status of traditional ethnic music has been shaken as rock music and pop music have rapidly developed since the reform and opening-up. This study is to consider the possibilities and problems in securing popularity of ethnic music focusing on the ethnic music group, 12 Girls Band, which has gained large popularity in China and Japan recently. Therefore, their representative songs were selected by dividing them into the era of rising where they had attracted a large popularity before 2009 and of falling where they had failed to attract huge audience losing popularity. Analyzing this, their musical characteristics were identified and the reasons behind the rise and fall of their popularity were analyzed. Futhermore, we hope to contribute to promote the national culture by suggesting ways to preserve ethnic music through production and promotion strategies of its attractiveness in order to popularize ethnic music and to make it loved by the music industry continuously.

Individualized Treatment of Allergic Rhinitis According to Nasal Cytology

Jianjun Chen,Yue Zhou,Li Zhang,Yanjun Wang,Amber N. Pepper,Seong H. Cho,Weijia Kong 대한천식알레르기학회 2017 Allergy, Asthma & Immunology Research Vol.9 No.5

Purpose: Nasal cytology is important in the diagnosis and treatment of nasal inflammatory diseases. Treatment of allergic rhinitis (AR) according to nasal cytology has not been fully studied. We plan to explore the individualized treatment of AR according to nasal cytology. Methods: Nasal cytology from 468 AR patients was examined for inflammatory cell quantity (grade 0-5) and the percentage of neutrophils and eosinophils. Results were subdivided into the following categories: AR(Eos), eosinophil ≥50% of the whole inflammatory cells; AR(Neu), neutrophils ≥90%; AR(Eos/Neu), 10%≤ eosinophil <50%; AR(Low), grade 0/1 inflammatory cell quantity. Nasal cytology-guided treatment was implemented: all AR(Eos) patients (n=22) and half of the AR(Neu) patients (AR[Neu1], n=22) were treated with mometasone furoate spray and oral loratadine. Another half of the AR(Neu) patients (AR[Neu2], n=22) were treated with oral clarithromycin. Visual analog scale (VAS), symptom scores, and nasal cytology were evaluated 2 weeks before and after treatment. Results: There were 224/468 (47.86%) AR(Eos), 67/468 (14.32%) AR(Neu), 112/468 (23.93%) AR(Eos/Neu), and 65/468 (13.89%) AR(Low) of the AR patients studied. There were no significant differences in clinical characteristics among these subgroups, except that the nasal blockage score was higher in AR(Eos) patients than in AR(Neu) patients (1.99 vs 1.50, P=0.02). Comparing AR(Eos) patients with AR(Neu1) patients 2 weeks after treatment, nasal symptoms and VAS were significantly lower in AR(Eos) patients, except for nasal blockage symptoms (P<0.05 of nasal itching and sneezing; P<0.01 for nasal secretion, total scores, and VAS). Comparing AR(Neu1) with AR(Neu2) patients, nasal symptoms, and VAS were significantly lower in AR(Neu2), except for nasal blockage and nasal itching symptoms (P<0.05 for nasal secretions, sneezing, total score, and VAS). Conclusions: Nasal cytology may have important value in subtyping AR and optimizing AR treatment. Treating neutrophils is very important in AR patients with locally predominant neutrophils.

Robot Manipulator Visual Servoing via Kalman Filter- Optimized Extreme Learning Machine and Fuzzy Logic

Zhiyu Zhou,Yanjun Hu,Jiangfei Ji,Yaming Wang,Zefei Zhu,Donghe Yang,Ji Chen 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.8

Visual servoing (VS) based on the Kalman filter (KF) algorithm, as in the case of KF-based image-based visual servoing (IBVS) systems, suffers from three problems in uncalibrated environments: the perturbation noises of the robot system, error of noise statistics, and slow convergence. To solve these three problems, we use an IBVS based on KF, African vultures optimization algorithm enhanced extreme learning machine (AVOA-ELM), and fuzzy logic (FL) in this paper. Firstly, KF online estimation of the Jacobian matrix. We propose an AVOA-ELM error compensation model to compensate for the sub-optimal estimation of the KF to solve the problems of disturbance noises and noise statistics error. Next, an FL controller is designed for gain adaptation. This approach addresses the problem of the slow convergence of the IBVS system with the KF. Then, we propose a visual servoing scheme combining FL and KF-AVOA-ELM (FL-KF-AVOA-ELM). Finally, we verify the algorithm on the 6-DOF robotic manipulator PUMA 560. Compared with the existing methods, our algorithm can solve the three problems mentioned above without camera parameters, robot kinematics model, and target depth information. We also compared the proposed method with other KF-based IBVS methods under different disturbance noise environments. And the proposed method achieves the best results under the three evaluation metrics.