학계동향 : 이율곡의 사회사상과 역사철학

채무송 ( Mao Song Cai ),지준호(역) ( Chun Ho Chi ) 한국철학사연구회 2007 한국 철학논집 Vol.0 No.20

Application of the body force method in the rim driven thruster

Cai Boao,Tian Binbin,Qiu Liaoyuan,Xu Qing,Mao Xiaofei,He Wei,Chai Wei 대한조선학회 2022 International Journal of Naval Architecture and Oc Vol.14 No.1

The Rim Driven Thruster (RDT) has become a popular ship propulsion system in recent years. Due to the complex structure of RDT, a great number of computational resources are required to study the interaction between RDT and hull by adopting the discretized propeller method. This research looks into a modified body force method which is suitable for the RDT. To simulate self-propulsion of a trawler with a rim driven thruster, the Reynolds-averaged NaviereStokes (RANS) solver is used. In the modified body force method, three virtual disks are adopted to replace the propeller and rim rotors. Before correction, the interactions among the duct, the rim rotors and the propeller were studied. Through the analysis, it is found that the most suitable scheme is to take the open water curves of the propeller, of the “rotors þ duct” and of the RDT as the references for modification. The ducted virtual disks open water curve is modified in open water simulations until the result is consistent with the RDT open water calculation results. When used to self-propulsion simulation, the modified body force method is accurate and can roughly characterize the flow fields. The modified body force method saves a huge number of grids when compared to the discretized propeller method. Furthermore, the interaction between the ship and the RDT can be accurately modeled, which is critical for quickly predicting self-propulsion in ships equipped with rim driven thrusters. Finally, the modified body force method in this work is named as the body force RDT method.

Numerical study of 10-year-old child forearm injury

Mao, Haojie,Cai, Yun,Yang, King H. Techno-Press 2014 Advances in biomechanics & applications Vol.1 No.3

Forearm fractures in children are very common among all pediatric fractures. However, biomechanical investigations on the pediatric forearm are rather scarce, partially due to the complex anatomy, closely situated, interrelated structures, highly dynamic movement patterns, and lack of appropriate tools. The purpose of this study is to develop a computational tool for child forearm investigation and characterize the mechanical responses of a backward fall using the computational model. A three-dimensional 10-year-old child forearm finite element (FE) model, which includes the ulna, radius, carpal bones, metacarpals, phalanges, cartilages and ligaments, was developed. The high-quality hexahedral FE meshes were created using a multi-block approach to ensure computational accuracy. The material properties of the FE model were obtained by scaling reported adult experimental data. The design of computational experiments was performed to investigate material sensitivity and the effects of relevant parameters in backward fall. Numerical results provided a spectrum of child forearm responses with various effective masses and forearm angles. In addition, a conceptual L-shape wrist guard design was simulated and found to be able to reduce child distal radius fracture.

A Field Theory Based Model for Identifying the Effect of Organizational Structure on the Formation of Organizational Culture in Construction Projects

Peng Mao,Shuai Li,Kunhui Ye,Hubo Cai 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.1

A carefully selected organizational structure paves the way for the success of a construction project by fostering a strong and enduring organizational culture. However, very little research has been conducted regarding the effect of organizational structure on the formation of organizational culture. This research employs the field theory to demonstrate organizational culture development and thereafter proposes a novel model for identifying the effect of organizational structure on the formation of organizational culture in a construction project. An empirical analysis based on the Chinese construction industry is performed to verify the proposed model. The primary contribution of this research is twofold. First, it presents a new perspective of examining organizational culture development from organizational structure by using the cultural field theory. Second, it reveals the important effect of organizational structure on the formation of organizational culture and offers project owners a new approach for identifying the effect which could also be a reference for further selecting an appropriate organizational structure.

Reinforcement of Waterborne Polyurethane Films with Poly(acrylic acid)-Modified Palygorskite Fibers

Yu Mao,Lingli Ni,Changyou Yang,Peng Cai,Weigang Du,Xiaoyan Gao 한국섬유공학회 2020 Fibers and polymers Vol.21 No.9

Palygorskite (PAL) is a natural fibrous clay mineral which attracted tremendous attention as reinforcing agent topolymers. In this paper, a facile and environmental friendly modification process of PAL by poly acrylic acid (PAA) via insitupolymerization in PAL/water gel has been reported. The effects of PAA modified PAL (PAA-PAL) on the mechanical andthermal properties of waterborne polyurethane (WPU) nanocomposites have been investigated. Scanning electronmicroscopy (SEM) demonstrated that the dispersion of PAL has improved dramatically after PAA modification. Tensile testsshowed that PAA-PAL has a significant reinforcement effect on WPU matrix. Addition of 10 wt% PAA-PAL, the tensilestrength and the Young’s modulus of WPU composites increased 235 % and 388 %, respectively. Furthermore, the thermalstability of WPU also has been distinctly improved via addition of PAA-PAL.

Approach for Decoupling the Non-Linear Cross-Talk in a Six-Dimensional Force Platform

Zhiyong Mao,Ping Cai,Dian Wang,Rui Ji 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.3

As the primary equipment for balance function assessment, the six-dimensional force platform (SDFP) should maintain its quality for long term use. Unfortunately the inevitable cross-talk will deteriorate its comprehensive performance. Obtaininga new sensitivity coefficient matrix through re-calibration is an effective way to guarantee the measurement accuracy. Generalized force loading can be used for in-situ calibration, but the calibration result depends on the selected set of loading point when the components are nonlinearly coupled.This study attempts to find an appropriate loading point set to obtain the optimal decoupling matrix for the SDFP when non-linearcoupling exists. The decoupling design of strain gauge layout and the non-linear coupling resulting from the bending deformation of the top plate are analyzed. Based on the analysis, a digital simulation is conducted to investigate the relationship between the decoupling performance and the selection of the loading points. The simulation results show that the center distance of the loading point is the primary factor affecting the decoupling performance. An in-situ calibration is conducted, and the orthogonal test rule is used to evaluate the performance of the system. A comparison of the results shows that the experimental results agree with those of the simulations.

Dynamics of shearing force and its correlations with chemical compositions and in vitro dry matter digestibility of stylo (Stylosanthes guianensis) stem

Xuejuan Zi,Mao Li,Hanlin Zhou,Jun Tang,Yimin Cai 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.12

Objective: The study explored the dynamics of shearing force and its correlation with chemical compositions and in vitro dry matter digestibility (IVDMD) of stylo. Methods: The shearing force, diameter, linear density, chemical composition, and IVDMD of different height stylo stem were investigated. Linear regression analysis was done to determine the relationships between the shearing force and cut height, diameter, chemical composition, or IVDMD. Results: The results showed that shearing force of stylo stem increased with plant height increasing and the crude protein (CP) content and IVDMD decreased but fiber content increased over time, resulting in decreased forage value. In addition, tall stem had greater shearing force than short stem. Moreover, shearing force is positively correlated with stem diameter, linear density and fiber fraction, but negatively correlated with CP content and IVDMD. Conclusion: Overall, shearing force is an indicator more direct, easier and faster to measure than chemical composition and digestibility for evaluation of forage nutritive value related to animal performance. Therefore, it can be used to evaluate the nutritive value of stylo.

Predictive Potential of Glutathione S-Transferase Polymorphisms for Prognosis of Osteosarcoma Patients on Chemotherapy

Zhang, Shai-Lin,Mao, Ning-Fang,Sun, Jun-Ying,Shi, Zhi-Cai,Wang, Bing,Sun, Yong-Jian Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.6

Objective: To evaluate the predictive value of glutathione S-transferase (GST) gene polymorphisms for the prognosis of osteosarcoma patients receiving chemotherapy. Methods: A total of 159 patients were included in our study between January 2005 and December 2007., with follow-up until January 2012. Genotyping was based upon the duplex polymerase-chain-reaction with the PCR-CTPP method. Results: At the time of diagnosis, 15.4% of the patients presented with metastasis, while 22.3% developed metastasis during follow-up. At the time of final analysis on January 2012, the median follow-up was 45.5 months. Patients with null GSTM1 and GSTT1 had a higher event free survival rate than non-null genotype, but no significant association was found between the two genotypes and prognosis of osteosarcoma. Individuals with GSTP1 Val/Val genotype tended to live shorter than with the IIe/IIe genotype, and we found a significantly higher risk of death from osteosarcoma (adjusted HR=2.35, 95% CI=1.13-4.85). Conclusion: The GSTP1 gene polymorphism may have an important role in the prognosis of osteosarcoma patients with chemotherapy. Further analyses with larger samples and more genes encoding metabolizing and DNA repair enzymes are warranted.

The establishment of IB-SEM numerical method and verification of fluid-solid interaction

Wang, Jing,Li, Shu-cai,Mao, Xuerui,Li, Li-ping,Shi, Shao-shuai,Zhou, Zong-qing Techno-Press 2018 Geomechanics & engineering Vol.15 No.6

The interaction between particles and fluid was investigated by IB-SEM numerical method which is a combination of combing the spectral/hp element method and the rigid immersed boundary method. The accuracy of this numerical method was verified based on the computed results with the traditional body-fitted mesh in numerical simulation of the flow through the cylinder. Then the governing equations of particles motion and contact in fluid are constructed. The movement of the particles and the interaction between the fluid and the particles are investigated. This method avoided the problem of low computational efficiency and error caused by the re-division of the grid when the solids moved. Finally, the movement simulation of multi particles in the fluid was carried out, which can provide a completely new numerical simulation method.

Pseudo-homogeneous kinetic modeling of dioctyl terephthalate (DOTP) production by esterification of terephthalic acid and 2-ethylhexanol over tetrabutyl titanate catalyst

Feng Zhou,Jinjin Cai,Xiaoning Mao,Zhenyu Wu,Yong Nie 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.9

As a green plasticizer, the industrial production of dioctyl terephthalate (DOTP) is still facing the problemof high energy consumption. To optimize the production process and reactor, it is essential to understand the kineticbehavior of reaction system. In this work, the two-step consecutive esterification of solid terephthalic acid (PTA) and 2-ethylhexanol (2-EH) catalyzed by tetrabutyl titanate was studied. First, the equilibrium constants and enthalpies of thetwo-step reaction were experimentally determined and validated by the group contribution methods. Then, a pseudohomogeneouskinetic model was developed, and the reaction order of PTA was corrected to reflect its solid phase characteristic. Non-isothermal kinetic experiments were carried out under different initial feed molar ratios and catalystconcentrations, and the kinetic parameters in the model were estimated by mathematical regression. The model predicteddata agreed well with the experimental data. Finally, the analyses of reaction rate showed that the first-step reactionwas the rate-controlling step of the whole esterification process.