Adaptive control of a vehicle-seat-human coupled model using quasi-zero-stiffness vibration isolator as seat suspension

Yong Wang,Shunming Li,Chun Cheng,Yuqing Su 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.7

We propose the quasi-zero-stiffness (QZS) vibration isolator as seat suspension to improve vehicle vibration isolation performance. The QZS vibration isolator is composed of vertical spring and two symmetric negative stiffness structures used as stiffness correctors. A vehicle-seat-human coupled model considering the QZS vibration isolator is established as a three degree-of-freedom (DOF) model; it is composed of a quarter car model and a simplified 1 DOF model combined vehicle seat and human body. This model considers the changing mass of the passengers and sets the total mass of the vehicle seat and human body as an uncertain parameter, which investigates the overload and unload conditions in practical engineering. To further improve the vehicle ride comfort, a constrained adaptive backstepping controller law based on the barrier Lyapunov function (BLF) is presented. The dynamic characteristic of the active vehicle-seathuman coupled model under shock excitation was analyzed using numerical method. The results show that the designed controller law can isolate the shock excitation transmitted from the road to the passengers effectively, and both the vehicle and seat suspension strokes remain in the allowed stroke range.

Comparative Genomic Analysis Reveals That the 20K and 38K Prophages in Listeria monocytogenes Serovar 4a Strains Lm850658 and M7 Contribute to Genetic Diversity but Not to Virulence

( Chun Fang ),( Tong Cao ),( Ying Shan ),( Ye Xia ),( Yong Ping Xin ),( Chang Yong Cheng ),( Houhui Song ),( John Bowman ),( Xiao Liang Li ),( Xiang Yang Zhou ),( Wei Huan Fang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.1

Listeria monocytogenes is a foodborne pathogen of considerable genetic diversity with varying pathogenicity. Initially, we found that the strain M7 was far less pathogenic than the strain Lm850658 though both are serovar 4a strains belonging to the lineage III. Comparative genomic approaches were then attempted to decipher the genetic basis that might govern the strain-dependent pathotypes. There are 2,761 coding sequences of 100% nucleotide identity between the two strains, accounting for 95.7% of the total genes in Lm850658 and 92.7% in M7. Lm850658 contains 33 specific genes, including a novel 20K prophage whereas strain M7 has 130 specific genes, including two large prophages (38K and 44K). To examine the roles of these specific prophages in pathogenicity, the 20K and 38K prophages were deleted from their respective strains. There were virtually no differences of pathogenicity between the deletion mutants and their parent strains, although some putative virulent factors like VirB4 are present in the 20K region or holin-lysin in the 38K region. In silico PCR analysis of 29 listeria genomes show that only strain SLCC2540 has the same 18 bp integration hotspot as Lm850658, whereas the sequence identity of their 20K prophages is very low (21.3%). The 38K and 44K prophages are located in two other different hotspots and are conserved in low virulent strains M7, HCC23, and L99. In conclusion, the 20K and 38K prophages of L. monocytogenes serovar 4a strains Lm850658 and M7 are not related to virulence but contribute to genetic diversity.

중국 조선족 중학생의 자아정체성과 사회정체성의 관계

성춘향(Cheng Chun xiang),이예화(Li Yi hua),박용한(Park Yong han) 한국열린교육학회 2017 열린교육연구 Vol.25 No.1

본 연구에서는 문화적·지리적·정치적으로 복잡다단한 사회적 맥락에 놓여있는 중국 조선족 청소년들의 자아정체성과 사회정체성의 발달 및 그 관계를 살펴보고, 이러한 정체성 발달에서의 양상이 조선족학교와 한족학교라는 학교 특성에 따라 어떻게 다르게 나타나는지 살펴보고자 하였다. 이를 위해, 중국 연변지역의 4개 중학교(조선족학교 1개교, 한족중학교 3개교)에 다니고 있는 265명의 조선족 중학생을 대상으로 자아정체성과 사회정체성 발달 정도를 알아보기 위해 설문을 실시하였다. 주요 연구결과는 다음과 같다. 첫째, 조선족학교와 한족학교에 다니는 조선족 중학생들은 자아정체성에서는 차이가 없었지만 사회정체성의 경우 하위변인에 따라 차이가 있었다. 사회정체성 하위변인 중 민족정체성은 조선족학교 학생들이 한족학교 학생들보다 높았고, 이와 반대로 독립정체성과 국민정체성은 한족학교에 다니는 조선족 중학생들이 더 높았다. 둘째, 조선족 중학생들의 사회정체성과 자아정체성간의 관계를 살펴본 분석 결과에서는 조선족학교에 다니는 조선족 중학생들의 경우 사회정체성 중 독립정체성이 높을수록 미래확신성과 자기수용성을 포함하여 더 긍정적인 자아정체성을 갖는 것으로 나타났다. 이러한 연구결과는 다문화와 세계시민시대를 살아가는 청소년들에게 주류 대 비주류로서의 정체성이 아니라 자신이 속해 있는 사회적 집단의 고유성과 전통을 이어감과 동시에 타 집단 및 타 시대와의 다름을 인정하고 수용하며 이를 통해 새로운 정체성을 형성할 수 있도록 하는 교육과 환경의 필요성을 시사해 주었다. This study explored the development of self-identity and social identity as well as their relations for Korean-Chinese students living in a complicated cultural, geographical, and political context. In addition, the research examined how those results would be differentiated by the characteristics of the schools the students attended: Korean-Chinese ethnic schools and general Chinese schools. For these purposes, the study administered a survey of self-identity and social identity to 265 Korean-Chinese middle school students in one Korean-Chinese ethnic school and three general Chinese schools. Main results are as follows. First, no difference was found in self-identity while there were some differences in social identity between two types of schools. Specifically, among the sub-components of social identity, ethnic identity was higher for Korean-Chinese students in the Korean-Chinese ethnic school than those in the Chinese schools. Meanwhile, independent identity and national identity were higher for Korean-Chinese students attending general Chinese schools than those in the ethnic school. Second, only for Korean-Chinese students attending the ethnic school, higher independent identity significantly predicted more positive self-identity especially such as future confidence and self-acceptance. These results suggest that proper education and environment should be provided for adolescents living in the era of multi-culturalism and global citizenship in order for them to develop not conventional identity as majority or minority but new identity through accepting and appreciating their differences from other groups or generations while keeping the characteristics and tradition of the social group they belong to.

Effect of Trichostatin A on CNE2 Nasopharyngeal Carcinoma Cells - Genome-wide DNA Methylation Alteration

Yang, Xiao-Li,Zhang, Cheng-Dong,Wu, Hua-Yu,Wu, Yong-Hu,Zhang, Yue-Ning,Qin, Meng-Bin,Wu, Hua,Liu, Xiao-Chun,Lina, Xing,Lu, Shao-Ming Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.11

Trichostatin A (TSA) is a histone deacetylase (HDAC) inhibitor. We here investigated its effects on proliferation and apoptosis of the CNE2 carcinoma cell line, and attempted to establish genome-wide DNA methylation alteration due to differentially histone acetylation status. After cells were treated by TSA, the inhibitory rate of cell proliferation was examined with a CCK8 kit, and cell apoptosis was determined by flow cytometry. Compared to control, TSA inhibited CNE2 cell growth and induced apoptosis. Furthermore, TSA was found to induce genome-wide methylation alteration as assessed by genome-wide methylation array. Overall DNA methylation level of cells treated with TSA was higher than in controls. Function and pathway analysis revealed that many genes with methylation alteration were involved in key biological roles, such as apoptosis and cell proliferation. Three genes (DAP3, HSPB1 and CLDN) were independently confirmed by quantitative real-time PCR. Finally, we conclude that TSA inhibits CNE2 cell growth and induces apoptosis in vitro involving genome-wide DNA methylation alteration, so that it has promising application prospects in treatment of NPC in vivo. Although many unreported hypermethylated/hypomethylated genes should be further analyzed and validated, the pointers to new biomarkers and therapeutic strategies in the treatment of NPC should be stressed.

Theoretical research on the identification method of bridge dynamic parameters using free decay response

Tan, Guo-Jin,Cheng, Yong-Chun,Liu, Han-Bing,Wang, Long-Lin Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.38 No.3

Input excitation and output response of structure are needed in conventional modal analysis methods. However, input excitation is often difficult to be obtained in the dynamic load test of bridge structures. Therefore, what attracts engineers' attention is how to get dynamic parameters from the output response. In this paper, a structural experimental modal analysis method is introduced, which can be used to conveniently obtain dynamic parameters of the structure from the free decay response. With known damping coefficients, this analysis method can be used to identify the natural frequencies and the mode shapes of MDOF structures. Based on the modal analysis theory, the mathematical relationship of damping ratio and frequency is obtained. By using this mathematical relationship to improve the previous method, an improved experimental modal analysis method is proposed in this paper. This improved method can overcome the deficiencies of the previous method, which can not identify damping ratios and requires damping coefficients in advance. Additionally, this improved method can also identify the natural frequencies, mode shapes and damping ratios of the bridge only from the free decay response, and ensure the stability of identification process by using modern mathematical means. Finally, the feasibility and effectiveness of this method are demonstrated by a numerical example of a simply supported reinforced concrete beam.

Theoretical research on the identification method of bridge dynamic parameters using free decay response

Guo-jin Tan,Yong-chun Cheng,Han-bing Liu,Long-lin Wang 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.38 No.3

Input excitation and output response of structure are needed in conventional modal analysis methods. However, input excitation is often difficult to be obtained in the dynamic load test of bridge structures. Therefore, what attracts engineers’ attention is how to get dynamic parameters from the output response. In this paper, a structural experimental modal analysis method is introduced, which can be used to conveniently obtain dynamic parameters of the structure from the free decay response. With known damping coefficients, this analysis method can be used to identify the natural frequencies and the mode shapes of MDOF structures. Based on the modal analysis theory, the mathematical relationship of damping ratio and frequency is obtained. By using this mathematical relationship to improve the previous method, an improved experimental modal analysis method is proposed in this paper. This improved method can overcome the deficiencies of the previous method, which can not identify damping ratios and requires damping coefficients in advance. Additionally, this improved method can also identify the natural frequencies, mode shapes and damping ratios of the bridge only from the free decay response, and ensure the stability of identification process by using modern mathematical means. Finally, the feasibility and effectiveness of this method are demonstrated by a numerical example of a simply supported reinforced concrete beam.

Genetic Organization of ascB-dapE Internalin Cluster Serves as a Potential Marker for Listeria monocytogenes Sublineages IIA, IIB, and IIC

( Jian Shun Chen ),( Chun Fang ),( Ning Yu Zhu ),( Yong Hui Lv ),( Chang Yong Cheng ),( Yi Jiang Bei ),( Tianlun Zheng ),( Wei Huan Fang ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.5

Listeria monocytogenes is an important foodborne pathogen that comprises four genetic lineages: I, II, III, and IV. Of these, lineage II is frequently recovered from foods and environments and responsible for the increasing incidence of human listeriosis. In this study, the phylogenetic structure of lineage II was determined through sequencing analysis of the ascB-dapE internalin cluster. Fifteen sequence types proposed by multilocus sequence typing based on nine housekeeping genes were grouped into three distinct sublineages, IIA, IIB, and IIC. Organization of the ascBdapE internalin cluster could serve as a molecular marker for these sublineages, with inlGHE, inlGC2DE, and inlC2DE for IIA, IIB, and IIC, respectively. These sublineages displayed specific genetic and phenotypic characteristics. IIA and IIC showed a higher frequency of recombination (ρ/θ). However, recombination events had greater effect (r/m) on IIB, leading to its high nucleotide diversity. Moreover, IIA and IIB harbored a wider range of internalin and stress-response genes, and possessed higher nisin tolerance, whereas IIC contained the largest portion of low-virulent strains owing to premature stop codons in inlA. The results of this study indicate that IIA, IIB, and IIC might occupy different ecological niches, and IIB might have a better adaptation to a broad range of environmental niches.

藍전果忍冬科技生産示範園的建立與硏究

안봉운 ( Feng Yun An ),현영남 ( Yong Nan Xuan ),안영희 ( Young Hee Ahn ),김미란 ( Mei Lan Jin ),요점춘 ( Zhan Chun Yao ),양금화 ( Jin Hua Liang ),주청선 ( Qing Xian Zhou ),렴성철 ( Cheng Zhe Lian ),황빙군 ( Bing Jun Huang ),소보군 한국녹지환경디자인학회 2008 녹지환경학회지 Vol.4 No.2

Lonicera caerulea L. var. edulis Turcz et Herd. with great nutrient and commercial edible value, is a kind of wild berry resource in regions of Changbai Moutains, China. Systematic cultivation technology for its large-scale production is developed and formation of cultivated land with area of 150 hectares is established. With high-yield technology, the production yield can be increased by twice. Systematic cultivation technology and establishment of technology demonstration garden lay the foundation for construction of production base and large-scale production of Lonicera caerulea L. var. edulis Turcz et Herd.

A Multi-Inlet Microfluidic Nozzle Head with Shape Memory Alloy-Based Switching for Biomaterial Printing with Precise Flow Control

Karthick Mani,Wei-Chen Lin,Chun-Fang Wang,Bivas Panigrahi,Yong-Jin Wu,Cheng-Lung Wu,Chia-Yuan Chen 한국바이오칩학회 2020 BioChip Journal Vol.14 No.4

3D bioprinting is one of the rapidly evolving fields of tissue engineering where microengineering meets cells biology within an unprecedented precision to construct tissue structures of various forms with complexity. However, enabling simultaneous printing of heterogeneous biomaterial along with scaffold components through the currently available printers is still considered as a major challenge due to the lack of instrumentation. Flow control is one of the major issues associated with the process. In this aspect, a microfluidic nozzle head equipped with two shape-memory alloy (SMA) actuators was proposed and integrated with a commercially available 3D printer to assist the biomaterial printing in a more systematic manner. The SMA actuator restrains the amount of flows for fabricating the desired scaffold components. Experimental results illustrated that the use of SMA actuator ensued a rapid and precise flow control of biomaterial and can further facilitate to maintain the width of any printed structures. As a proof of concept for the profound biomedical applications with the present manufacturing configuration, a 3D printed hydrogel platform was fabricated with demonstrated characters for later cell seeding after the printing further opens a new chapter in terms of biomaterial printing.

감마선처리에 의한 핑크색 아네모네 화형의 분화용 국화 ‘포인트에그’ 육성

진영돈(Young-Don Chin),황주천(Ju-Cheng Hwang),정용모(Yong-Mo Chung),안동춘(Dong-Chun An),이병정(Byeong-Jeong Lee),이상대(Sang-Dae Lee) 한국원예학회 2015 한국원예학회 학술발표요지 Vol.2015 No.10