Climate and Air Pollution Mitigation Efforts Would both Require to Achieve New WHO Air Quality Targets

Shaohui Zhang 한국대기환경학회 2022 한국대기환경학회 학술대회논문집 Vol.2022 No.10

White Matter Microstructural Similarity and Diversity of Functional Constipation and Constipation-predominant Irritable Bowel Syndrome

( Jiaofen Nan ),( Liangliang Zhang ),( Qiqiang Chen ),( Nannan Zong ),( Peiyong Zhang ),( Xing Ji ),( Shaohui Ma ),( Yuchen Zhang ),( Wei Huang ),( Zhongzhou Du ),( Yongquan Xia ),( Ming Zhang ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2018 Journal of Neurogastroenterology and Motility (JNM Vol.24 No.1

Background/Aims The Rome III criteria separated chronic constipation into functional constipation (FC) and constipation-predominant irritable bowel syndrome (IBS-C), but some researchers questioned the partitioning and treated both as distinct parts of a continuum. The study aims to explore the similarity and diversity of brain white matter between FC and IBS-C. Methods The voxel-wise analysis of the diffusion parameters was used to quantify the white matter changes of female brains in 18 FC patients and 20 IBS-C patients compared with a comparison group with 19 healthy controls by tract-based spatial statistics. The correlations between diffusive parameters and clinical symptoms were evaluated using a Pearson’s correlation. Results In comparison to healthy controls, FC patients showed a decrease of fractional anisotropy (FA) and an increase of radial diffusivity (RD) in multiple major fibers encompassing the corpus callosum (CC, P = 0.001 at peak), external capsule (P = 0.002 at peak), corona radiata (CR, P = 0.001 at peak), and superior longitudinal fasciculus (SLF, P = 0.002 at peak). In contrast, IBS-C patients showed FA and RD aberrations in the CC (P = 0.048 at peak). Moreover, the direct comparison between FC and IBS-C showed only RD differences in the CR and SLF. In addition, FA and RD in the CC were significantly associated with abdominal pain for all patients, whereas FA in CR (P = 0.016) and SLF (P = 0.040) were significantly associated with the length of time per attempt and incomplete evacuation separately for FC patients. Conclusion These results may improve our understanding of the pathophysiological mechanisms underlying different types of constipation. (J Neurogastroenterol Motil 2018;24:107-118)

Stability analysis of wheeled mobile multirobot coordinated towing system

Xiangtang Zhao,Zhigang Zhao,Shaohui Zhang,Cheng Su 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.1

In the towing process of the wheeled mobile multi-robot coordinated towing system, the overturning of the mobile robot itself will lead to a series of problems such as system damage, operation failure and casualties. In order to adapt to the complex operating environment and complete the towing work safely and effectively, higher requirements are put forward for the carrying capacity, mobile performance and stability of the wheeled mobile multirobot coordinated towing system. Firstly, the spatial configuration of the wheeled multi-robot coordinated towing system is established and the kinematics of the manipulator and towing system are analyzed. The dynamic equations of the manipulator and towing system are established using the Lagrangian method and the Newton-Euler method. Then, the inverse kinematics of the robot is used to solve the joint angles, and the force-angle stability measure is used to analyze the law of overturning stability of the system under three cases of static, static stress and dynamic stress, respectively. Finally, the standard stability angles corresponding to the two sets of joint angles of the robot are compared with the simulation based on the program written in Matlab. The results show that the first set of joint angles has better stability, and some standard stability angles of the system are less than 0 during the motion, the towing system will overturn. Therefore, the first set of joint angles of the manipulator has better stability and should be selected to perform towing tasks. The joint angles of the manipulator should be adjusted to avoid overturning in practice.

Dynamics and workspace analysis of a multi-robot collaborative towing system with floating base

Jinghang Li,Zhigang Zhao,Shaohui Zhang,Cheng Su 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.10

A multi-robot collaborative towing system fixed on floating base for high load marine work was established in this paper, and its dynamics and workspace were analyzed. An improved Monte-Carlo method was optimized, considering that this method cannot be directly used for the multi-robot system. Firstly, according to the structure of the system, the dynamics equations of the towing mechanism and the floating base were established by using the Newton-Euler method and rigid body dynamics, respectively. Then, an improved Monte-Carlo method was optimized, and the specific steps of solving the dynamic workspace by the optimized method were provided. Lastly, the system was divided into three types according to the actuator, and their dynamic workspace were simulated with a practical example by the traditional Monte-Carlo method and the optimized method. The simulation results show that, compared with traditional method, the optimized method has higher efficiency and can figure a workspace with clear boundary. Results of this study lay a basis for the subsequent trajectory plan and stability analysis of the system.

Experimental modal test of the spiral bevel gear wheel using the PolyMAX method

Tieming Xiang,Diandian Lan,Shaohui Zhang,Wuxiong Li,Daoquan Lin 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.1

To verify the effectiveness and correctness of free modal analysis results from a Spiral bevel gear (SBG) wheel by using Finite element method (FEM), an experimental platform was constructed through the free-hanging support of the SBG wheel. The experiment used the hammer knock percussion for excitation and a three-directional acceleration sensor as signal acquisition equipment and utilized the LMS modal analysis module. The geometric model of the SBG wheel was constructed using an eight-node octagon instead of the SBG wheel outer contour. The experiment then extracted the modal parameters of the wheel using the PolyMAX method and obtained the first- and second-order natural frequencies, damping ratios, and mode shapes of the SBG wheel at 0-7 kHz during the experimental modal test. The results of the experimental test were compared with those of the FEM free modal analysis. The first- and second-order natural frequency error rates by FEM were 0.25 % and 0.45 %, respectively. The experimental modal test result verified the rationality of the model by FEM, thus showing that the result of modal analysis by FEM is reliable and providing a basis for the dynamic characteristic analysis of SBG.

Expansion, characterization, and differentiation of rabbit bone marrow-derived mesenchymal stem cells in serum-free medium

Lifang Jin,Jian Ni,Shaohui Ji,Mei Shen,Jianlong Zhang,Jiwei Han 한국통합생물학회 2014 Animal cells and systems Vol.18 No.4

Mesenchymal stem cells (MSCs) derived from rabbit bone marrow are routinely investigated in cardiovascularand orthopedic models for regenerative medicine application. However, classical medium used for generatingrabbit MSCs (rbMSCs) was supplemented with fetal bovine serum (FBS), which would raise several safetyconcerns and inconsistencies in the generation of MSCs. Here, we tested a serum-free medium for culture ofrbMSCs through the investigation of multiple parameters including cell morphology, expansion, phenotype,and trilineage differentiation. RbMSCs were isolated using the gradient centrifugation method, and expandedin StemPro® MSC SFM in the presence of substrates and basic fibroblast growth factor (bFGF). Cells werethen characterized by phase contrast microscopy observation, cell proliferation analysis, immunocytochemistrystaining, RT-PCR, and qPCR analysis. Similar to that achieved with FBS-containing culture medium, theviability and proliferation of rbMSCs were improved in serum-free medium supplemented with bFGF and precoatedwith CELLstartTM. Serum-free expanded rbMSCs showed the fibroblastic spindle-shape morphology,and were positive for CD29, CD44, and CD73, and negative for CD34, CD45, and CD166. After thecorresponding differentiation, rbMSCs from serum-free condition were demonstrated to differentiate intoadipogenic, osteogenic, and chondrogenic lineages. In addition, differences were also observed betweenrbMSCs cultured with or without serum in terms of their morphology, proliferation, and gene expression levelsof early differentiation transcription factors. In conclusion, this study demonstrates that rbMSCs can beexpanded in a serum-free condition while maintaining the original characteristics of MSCs, which provides auseful tool to understand the basic biological properties of rbMSCs in culture.

Research on Per-cell Codebook based Channel Quantization for CoMP Transmission

( Zhirui Hu ),( Chunyan Feng ),( Tiankui Zhang ),( Qiubin Gao ),( Shaohui Sun ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.6

Coordinated multi-point (CoMP) transmission has been regarded as a potential technology for LTE-Advanced. In frequency division duplexing systems, channel quantization is applied for reporting channel state information (CSI). Considering the dynamic number of cooperation base stations (BSs), asymmetry feature of CoMP channels and high searching complexity, simply increasing the size of the codebook used in traditional multiple antenna systems to quantize the global CSI of CoMP systems directly is infeasible. Per-cell codebook based channel quantization to quantize local CSI for each BS separately is an effective method. In this paper, the theoretical upper bounds of system throughput are derived for two codeword selection schemes, independent codeword selection (ICS) and joint codeword selection (JCS), respectively. The feedback overhead and selection complexity of these two schemes are analyzed. In the simulation, the system throughput of ICS and JCS is compared. Both analysis and simulation results show that JCS has a better tradeoff between system throughput and feedback overhead. The ICS has obvious advantage in complexity, but it needs additional phase information (PI) feedback for obtaining the approximate system throughput with JCS. Under the same number of feedback bits constraint, allocating the number of bits for channel direction information (CDI) and PI quantization can increase the system throughput, but ICS is still inferior to JCS. Based on theoretical analysis and simulation results, some recommendations are given with regard to the application of each scheme respectively.

Design of Intelligent Management and Service System for Gas Valve

Xiaoli Wang,Feifei Wang,Yuhou Song,Guirong Zhang,Shaohui Wang 한국정보처리학회 2020 Journal of information processing systems Vol.16 No.5

This paper introduces a design scheme of intelligent gas valve management and service system based onInternet. This scheme adds sensor and general packet radio service (GPRS) modules to the traditional gas valveand establishes communication connection between gas valve and the server through wireless packetcommunication technology, which makes the traditional gas valve have the networking ability. Compared withthe traditional gas valve management and service business, the method proposed in this paper is moreconvenient and efficient.

In Situ Growth of MOF-Derived NaCoPO4@Carbon for Asymmetric Supercapacitive and Water Oxidation Electrocatalytic Performance

Peng Guo,Zhaojie Wang,Hongyu Chen,Shaohui Ge,Chen Chen,Haowei Wang,Jinbao Zhang,Minglei Hua,Shuxian Wei,Xiaoqing Lu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.15 No.01

The increasing energy crisis promotes the study on novel electrode materials with high performance for supercapacitive storage and energy conversion. Transition metal phosphates have been reported as a potential candidate due to the unique coordination and corresponding electronic structure. Herein, we adopted a facile method for preparing NaCoPO4@C derived from a metal organic framework (MOF) as a bifunctional electrode. ZIF-67 was synthesized before a refluxing process with Na2HPO4 to form a precursor, which is transformed into the final product via calcination in different atmospheres. Specifically, the resultant NaCoPO4@C exhibits a high specific capacitance of 1178.7 F g -1 at a current density of 1 A g -1 for a supercapacitor. An asymmetric supercapacitor (ASC) assembled with active carbon displays a high capacitance of 163.7 F g -1 at 1 A g -1. In addition, as an oxygen evolution reaction (OER) catalyst, the NaCoPO4@C electrode requires only 299 mV to drive a current density of 10 mA cm -2. These results suggest that the rational design of MOF-derived NaCoPO4@C provides a variety of practical applications in electrochemical energy conversion and storage.

A self-powered β-Ga2O3/CsCu2I3 heterojunction photodiode responding to deep ultraviolet irradiation

Gao Ang,Jiang Weiyu,Ma Guoliang,Liu Zeng,Li Shan,Yan Zuyong,Sun Weiming,Zhang Shaohui,Tang Weihua 한국물리학회 2022 Current Applied Physics Vol.33 No.-

In this paper, a lead-free halide perovskite CsCu2I3 film with high stability was prepared by the anti-solvent assisted crystallization method. Then, we coupled it with Ga2O3 to prepare a corresponding heterojunction deep ultraviolet (UV) photodetector. After testing, we concluded that the photodetector is sensitive to 254 nm UV light. The photodetector has good reproducibility, and has an ultra-high photo-to-dark current ratio (PDCR) of more than 105. In addition, under a bias of 10 V and an illuminated intensity of 200 μW/cm2, the responsivity (R) and specific detectivity (D*) reached 20 mA/W and 107 cm Hz1/2 W 1 (Jones), and the external quantum efficiency (EQE) is 10%. Meanwhile, the prepared photodetector could operate at zero bias, i.e., self-powered operation, along with a photocurrent of about 1 nA under illumination with UV light intensity of 200 μW/cm2.