RSSCube : A Content Syndication and Recommendation Architecture

Zijie Tang,Kun Ma 보안공학연구지원센터 2014 International Journal of Database Theory and Appli Vol.7 No.4

The long non-coding RNA uc.4 influences cell differentiation through the TGF-beta signaling pathway

Zijie Cheng,Qijun Zhang,Anwen Yin,Mengwen Feng,Hua Li,Hailang Li,Yun Li,Lingmei Qian 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

In a previous study, we screened thousands of long non-coding RNAs (lncRNAs) to assess their potential relationship with congenital heart disease (CHD). In this study, uc.4 attracted our attention because of its high level of evolutionary conservation and its antisense orientation to the CASZ1 gene, which is vital for heart development. We explored the function of uc.4 in cells and in zebrafish, and describe a potential mechanism of action. P19 cells were used to investigate the function of uc.4. We studied the effect of uc.4 overexpression on heart development in zebrafish. The overexpression of uc.4 influenced cell differentiation by inhibiting the TGF-beta signaling pathway and suppressed heart development in zebrafish, resulting in cardiac malformation. Taken together, our findings show that uc.4 is involved in heart development, thus providing a potential therapeutic target for CHD.

Effects of different constrained boundary structures on the evolution of shock waves and vortexes in muzzle jets

Zijie Li,Hao Wang,Changshun Chen,Hexia Huang 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.10

A gun-track launcher that combines a balanced gun with a rocket track is an important technology for the non-destructive recovery of high-value projectile weapons. Given the restrictions imposed by the track and the interference caused by it, the muzzle jet of such launchers is significantly different from those of traditional artillery. Given this engineering background, this study examines the characteristics of the evolution of supersonic muzzle jets with different constrained boundaries. Results show that the structure of the muzzle jet undergoes a distortion that changes its symmetric circumferential shape into an asymmetric one, tilted above the center of the muzzle. Vortexes are generated below the track owing to lateral airflow, and their formation and evolution lead to significant changes in the pressure of the flow field. Moreover, the asymmetry of the flow field varies owing to the different structures of the side plates of the track, which leads to varying characteristics of the development of shock waves and vortexes in the muzzle jet. The content of this article provides a theoretical basis and necessary technical support for enriching the research connotation and engineering applications of shock wave fields.

Fuzzy Control Strategy for Course Correction of Omnidirectional Mobile Robot

Niu Zijie,Lu Qiang,Cui Yonjie,Sun Zhijun 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.9

Omnidirectional mobile robots (OMRs) based on the Mecanum wheel, often slide during driving and cause the actual course to deviate from the set heading. To improve the OMR course accuracy, we propose a fuzzyPI control algorithm that modifies the OMR course in real time, by analyzing the omnidirectional movement of the Mecanum wheel and the kinematic model of the OMR. fuzzification, fuzzy reasoning, and defuzzification, the robot’s heading is corrected in real time. Analysis of the yaw error of the robots, with and without the fuzzy PI control algorithm, show that the yaw error has been reduced from the original values of −2.5-0◦ and −10.5-0◦ down to −0.6-0.6◦ and −1-0◦ , when the robot travels a distance of 3.5 m in the longitudinal and transverse directions, respectively. Through experiments, the traditional PI control algorithm and fuzzy PI control algorithm are compared in terms of the robot heading-regulation performance. From the analysis of experimental data, we can see that, when the yaw error of an OMR with the fuzzy PI control algorithm is between 35 and 40◦, the adjustment time is sped up by 1.3 s and 1.2 s and overshoot angle is reduced by 7.7◦ and 4.3◦ , respectively, for longitudinal and transverse movements. Both experimental results show that the fuzzy PI control algorithm has good regulation performance and can achieve good control effects.

Numerical analysis of transient pressure variation in the condenser of a nuclear power station

Xinjun Wang,Zijie Zhou,Zhao Song,Qiankui Lu,Jiafu Li 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.2

To research the characteristics of the transient variation of pressure in a nuclear power station condenser under accident condition, a mathematical model was established which simulated the cycling cooling water, heat transfer and pressure in the condenser. The calculation program of transient variation characteristics was established in Fortran language. The pump’s parameter, cooling line’s organization, check valve’s feature and the parameter of siphonic water-collecting well are involved in the cooling water flow’s mathematical model. The initial conditions of control volume are determined by the steady state of the condenser. The transient characteristics of a 1000 MW nuclear power station’s condenser and cooling water system were examined. The results show that at the condition of plant-powersuspension of pump, the cooling water flow rate decreases rapidly and refluxes, then fluctuates to 0. The variation of heat transfer coefficient in the condenser has three stages: at start it decreases sharply, then increases and decreases, and keeps constant in the end. Under three conditions (design, water and summer), the condenser pressure goes up in fluctuation. The time intervals between condenser’s pressure signals under three conditions are about 26.4 s, which can fulfill the requirement for safe operation of nuclear power station.

AtMe : An Online Multi-tenant Social Networking Service in Campus

Kun Ma,Zijie Tang,Zhe Yang,Shuwei Yao 보안공학연구지원센터 2015 International Journal of Database Theory and Appli Vol.8 No.5

Recently, more and more undergraduates have turned Internet to find support and take part in society in campus. However, current SNS systems are not oriented to a specific campus. In this paper, we design an online multi-tenant social networking service in campus, including At Helper and At Society. At Helper aims at improving the success ratio of the help process with a multi-tenant architecture, and At Society provides social services using popular instant messaging mobile application. Both modules change the traditional operation and maintenance to rent services. Besides, the key innovative design, such as multi-tenancy and access-aware data cache, are discussed in detail.

Toward Fine-grained Data-level Access Control Model for Multi-tenant Applications

Kun Ma,Weijuan Zhang,Zijie Tang 보안공학연구지원센터(IJGDC) 2014 International Journal of Grid and Distributed Comp Vol.7 No.2

AERODYNAMIC CHARACTERISTICS OF MIRA FASTBACK MODEL IN EXPERIMENT AND CFD

Yingchao Zhang,Jintao Zhang,Kaiguang Wu,Zijie Wang,Zhe Zhang 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.4

The lasting high fuel cost has recently inspired the resurgence in drag reduction research for vehicles, which calls for a thorough understanding of the vehicle wake. The acknowledged MIRA fastback vehicle model is characterized by similar real vehicle geometry, thus it is especially suitable for the above purpose. In spite of a considerable number of previous investigations, our knowledge of flow around this model remains incomplete. This paper aims to visit turbulent flow structure behind this model. An investigation has been conducted to measure the near wake flow structure of the MIRA 1/8 scale mode, using both Particle Image Velocimetry (PIV) experimental method and Computational Fluid Dynamics (CFD) simulation method. In order to capture the flow structure accurately, PIV measurement was performed in different sections along three orthogonal directions, and the CFD method acquired additional simulation results to catch the better flow status. Through the maps of the time-averaged vorticity, the instantaneous vorticity and the handled velocity vector from the PIV and CFD methods, we found out the formation mechanism of the transient flow of fastback model and summed up the schematic of flow structure. This study not only analyzed the vortex shedding characteristics of turbulent near wake, but more importantly provided insight into the complex three-dimensional features of the flow structure in the wakes of MIRA fastback model.

Excitation of two-colored temporal solitons in a segmented quasi-phase-matching structure

Zeng, Xianglong,Ashihara, Satoshi,Wang, Zijie,Wang, Tingyun,Chen, Yuping,Cha, Myoungsik The Optical Society 2009 Optics express Vol.17 No.19

<P>We conducted a numerical study on the excitation of a two-colored temporal soliton in a segmented quasi-phase-matching (QPM) structure. The device has three parts: a periodic QPM grating for second-harmonic generation, a single domain for phase shift, and a periodic QPM grating for soliton evolution. The second harmonic pulse generated in the first grating works as a seed in the cascaded up-and-down conversions in the second grating. The numerical results showed that the second harmonic seeding enables the excitation of soliton pulses with an improved spatio-temporal intensity profile in a broad bandwidth of the wave-vector mismatch.</P>

Solution and analysis of VL combined seal lubrication model under the effect of wear

Yi Zhang,Siyang Xiong,Sipeng Zhong,Zijie Xiong,Qiang Yang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.11

Through the finite element calculation of VL combined seal models under different wear conditions, contact pressure distributions of models are obtained. Considering the coupling effect between seal deformation and lubricating oil film, a mathematical model of elastohydrodynamic lubrication for VL combined seal is established. Based on the theory of small deformation, the elastic deformation of VL composite seal under high pressure is obtained by the deformation influence coefficient matrix method. Considering the influence of sealing surface wear and surface roughness, the oil film thickness distribution and oil film pressure distribution of VL combined seal are solved by the finite difference method. The analysis results show the wear of VL combined seal, the decrease of viscosity, the increase of roughness and rotational speed can raise the thickness and pressure of lubricating oil film. The correctness of numerical simulation is verified by experimentally measuring the friction torque and leakage rate of seal.