Numerical simulation on the draft surge suppression of a Francis turbine by J-Groove

Changfu Jin,Qingsheng Wei,Young-Do Choi 한국유체기계학회 2013 유체기계 연구개발 발표회 논문집 Vol.2013 No.11

중국 충칭 영화의 공간 서사 연구

양창푸 ( Yang Changfu ) 한국영화교육학회 2023 영화교육연구 Vol.17 No.1

영화가 탄생할 때부터 공간적 요소는 서사의 가장 기본적인 수단이었고, 현존하는 영화 예술에 관한 논저들은 공간의 화제를 피할 수 없었다. 중국 영화 산업이 발전함에 따라 중국 충칭은 독특한 지리적 및 인문 공간으로 많은 영화 제작진이 촬영 및 현지 인문 환경을 기반으로 한 영화를 제작하도록 끌어들였다. 이 글은 주로 충칭 영화의 공간 서사를 논했다. 분석 대상은 충칭 영화의 대표 작품<훠궈 전쟁>을 중심으로 한다. 이 영화는 충칭의 독특한 문화공간과 도시공간과 역사 공간을 배경으로 서사를 풀어냈다. 영화에서 중국 충칭의 공간이 영화의 서사에 어떤 역할을 하느냐가 주요 질문이다. 충칭 영화의 창작자는 영화 초반 영화 서사의 중요한 공간을 보여주며 영화 속 인물의 출현과 인물의 행동에 대한 배경적 토대를 제공하는 동시에 공간에 등장하는 인물의 운명을 응시한다. 인물은 다른 공간에 나타나서 다른 반응과 행동을 한다. 공간은 서사의 발전을 촉진하고 다음 서사 발전의 단서가 된다. Since the birth of film, the element of space has been its most basic means of narrative, and none of the existing treatises on film art can avoid the topic of space. With the development of China's film industry, Chongqing China's unique geographical and cultural space has attracted a large number of film production teams to shoot and create films based on the local cultural environment. This paper mainly discusses the spatial narrative of Chongqing movies, and the analysis object is centered on the representative work of Chongqing movies Hot Pot Heroes. This movie makes full use of Chongqing's unique cultural space, urban space and historical space for narrative. The question raised in this paper is mainly what effect the space of Chongqing, China in the film has on the narrative of the film. The creators of Chongqing films usually display the important space of the film narrative at the beginning of the film, providing a background basis for the appearance and behavior of the characters in the film, and at the same time gazing at the fate of the characters in the space. Characters appear in different spaces and react and act differently. Space promotes the development of the narrative and becomes the clue for the subsequent development of the narrative. On the other hand, metaphor is also an important function of space in Chongqing films. Using opposing characters to complete the metaphor of the light and dark aspects of human nature. Use the meteorology that appears in nature or the interaction between urban buildings and people to carry out the metaphor of human destiny. The various spaces interact and complement each other to complete and enrich the narrative of the film.

The Influence of Non-synchronous Excavation of Twin Curved Shield Tunnels

Shaohua Li,Changfu Huang,Tiejun Yao,Pengfei Li 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.5

The theoretical model of twin curved shield tunnels and refined numerical model considering the characteristics of wedge-shaped segment ring joints were established in this paper. Two construction schemes of taking the inner side or outer side of the twin curved tunnels as the first tunnel were conducted for comparison. Then two main characteristics of curved tunnel construction (over-excavation and yaw excavation loadings) were taken as variables to explore their response to the approaching construction caused by unsynchronized driving of twin curved shield tunnels. The ground surface settlement troughs obtained by the analytical solution and numerical simulation are in good agreement with the monitoring result. On the condition that the curved tunnel at the inner side is taken as the first tunnel, the excavation will intensify the ground settlement and the internal forces of its segment. In the case that the overcutting gap is not of large volume, it is advisable to first excavate the curved tunnel at the outer side, and then construct the curved tunnel at the inner side. The influence of soil loss on the ground disturbance is greater than that of construction loadings. The excessive overcutting gap not only easily induces a sharp increase in the ground vertical displacement, but also may lead to the movement of soil at the inner and middle sides towards the inner side of the curved tunnels, and causes the soil at the outer side to move towards the outer side of the curved tunnels. Remarkably, excessive overcutting gap may lead to large horizontal displacements of the ground surface.

Sulfation diffusion model for SO2 capture on the T-T sorbent at moderate temperatures

Yuran Li,Changfu You,Haiying Qi,Lizhai Yang 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.4

A sulfation model was developed for dry flue gas desulfurization (FGD) at moderate temperatures to describe the reaction characteristics of the T-T sorbent clusters and the fine CaO particles that fall off the sorbent grains in a circulating fluidized bed (CFB) reactor. The cluster model describes the calcium conversion and reaction rate for various size sorbent clusters. The sulfation reaction is first order with respect to the SO2 concentration above 973 K. The calcium conversion and reaction rate for the CaO particles were obtained by extrapolation. In the model for CaO particle, the reaction rate is linearly related to the calcium conversion and the SO2 concentration in the rapid reaction stage and linearly related only with the calcium conversion after the product layer forms. The sulfation model accurately describes the sulfation of the T-T sorbent flowing through a CFB reactor.

Experimental and numerical investigation on the pyrolysis of single coarse lignite particles

Kai Zhang,Changfu You,Yulei Li 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.4

This paper reports on the mathematical modeling of the pyrolysis of single coarse lignite particles using a kinetics model coupled with a heat transfer model. The parallel reaction kinetics model of the lignite pyrolysis makes no assumptions about the activation energy distribution and the conversion of sub-reactions. The pyrolysis kinetics parameters were obtained on the basis of experimental data from thermogravimetric analysis (TGA) tests. The heat transfer model includes diffusive, convective and radiative heat transfer modes. The experimental investigations were carried out for single lignite particles in an electrically heated reactor. Measurements of the temperature and mass loss were performed during the pyrolysis in a nitrogen atmosphere. The model predictions for the temperature and mass loss histories agree well with the experimental data, verifying that the mathematical model accurately evaluates the pyrolysis of lignite particles. The effects of temperature and particle size on the pyrolysis time and final residual mass fraction were evaluated using the numerical model.

Experimental and model investigation on the mass balance of a dry circulating fluidized bed for flue gas desulfurization system

Yuan Li,Changfu You 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.9

A moderate temperature dry circulating fluidized bed flue gas desulfurization (CFB-FGD) process was developed using rapidly hydrated sorbent. This technique has the advantages of low cost, no water consumption, and a valuable dry product CaSO_4. To keep the system operation stable, a mass balance model, based on cell model considering flow state, particle abrasion, particle residence time, particle segregation and desulfurization processes, was built to predict the system state and optimize the operating condition. Experimental studies were conducted on a pilotscale CFB-FGD system with rapidly hydrated sorbent made from CFB circulating ash and lime (circulating ash sorbent)or coal fly ash and lime (coal fly ash sorbent). Calculated results were compared with experimental results and the relative error was less than 10%. The results indicated that feed sorbent mass, feed sorbent size, superficial gas velocity, particle abrasion coefficient and cyclone efficiency had significant influence on the mass balance of CFB system. The circulating ash sorbent was better than the coal fly ash sorbent, for providing higher desulfurization efficiency and being better for the CFB-FGD system to achieve mass balance.

TRAJECTORY PLANNING FOR AUTOMATED PARKING SYSTEMS USING DEEP REINFORCEMENT LEARNING

Zhuo Du,Qiheng Miao,Changfu Zong 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.4

Deep reinforcement learning (DRL) has been successfully adopted in many tasks, such as autonomous driving and gaming, to achieve or surpass human-level performance. This paper proposes a DRL-based trajectory planner for automated parking systems (APS). A thorough review of literature in this field is presented. A simulation study is conducted to investigate the trajectory planning performance of the parking agent for: (i) different neural-network architectures; (ii) different training set-ups; (iii) efficacy of human-demonstration. Real-time capability of the proposed planner on various embedded hardware platforms is also discussed by the paper, showing promising performance. Insights of the use of DRL for APS are concluded at the end of the paper.

Study of Constant Current-Constant Voltage Output Wireless Charging System Based on Compound Topologies

Linlin Tan,Shulei Pan,Changfu Xu,Changxin Yan,Han Liu,Xueliang Huang 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.4

Wireless power transfer (WPT) technology has the advantages of intelligence and facilitation. This paper designs a WPT system applied to battery charging and provides a strategy which switches from the constant current (CC) charging mode to constant voltage (CV) charging mode. The LCL-LCL topology is used to realize the CC output, while the LCL-S (series compensation) topology is used to realize the CV output. The main factor affecting the output characteristics is extracted by analyzing the two topologies above. Based on the main factor, this paper puts forward a modified way to design the system. In addition, on-line monitors for the battery and switches are placed at receiving side, which avoids the need for introducing an information interaction module into the system. Therefore, the complexity of the controlling system is reduced. Finally, simulation and experimental analyses are carried out to verify the correctness of the compound topologies.

Severe choline deficiency induces alternative splicing aberrance in optimized duck primary hepatocyte cultures

Zhao Lulu,Cai Hongying,Wu Yongbao,Tian Changfu,Wen Zhiguo,Yang Peilong 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.11

Objective: Choline deficiency, one main trigger for nonalcoholic fatty liver disease (NAFLD), is closely related to lipid metabolism disorder. Previous study in a choline-deficient model has largely focused on gene expression rather than gene structure, especially sparse are studies regarding to alternative splicing (AS). In modern life science research, primary hepatocytes culture technology facilitates such studies, which can accurately imitate liver activity in vitro and show unique superiority. Whereas limitations to traditional hepatocytes culture technology exist in terms of efficiency and operability. This study pursued an optimization culture method for duck primary hepatocytes to explore AS in choline-deficient model. Methods: We performed an optimization culture method for duck primary hepatocytes with multi-step digestion procedure from Pekin duck embryos. Subsequently a NAFLD model was constructed with choline-free medium. RNA-seq and further analysis by rMATS were performed to identify AS events alterations in choline-deficency duck primary hepatocytes. Results: The results showed E13 (embryonic day 13) to E15 is suitable to obtain hepatocytes, and the viability reached over 95% by trypan blue exclusion assay. Primary hepatocyte retained their biological function as well identified by Periodic Acid-Schiff staining method and Glucose-6-phosphate dehydrogenase activity assay, respectively. Meanwhile, genes of alb and afp and specific protein of albumin were detected to verify cultured hepatocytes. Immunofluorescence was used to evaluate purity of hepatocytes, presenting up to 90%. On this base, choline-deficient model was constructed and displayed significantly increase of intracellular triglyceride and cholesterol as reported previously. Intriguingly, our data suggested that AS events in choline-deficient model were implicated in pivotal biological processes as an aberrant transcriptional regulator, of which 16 genes were involved in lipid metabolism and highly enriched in glycerophospholipid metabolism. Conclusion: An effective and rapid protocol for obtaining duck primary hepatocytes was established, by which our findings manifested choline deficiency could induce the accumulation of lipid and result in aberrant AS events in hepatocytes, providing a novel insight into various AS in the metabolism role of choline. Objective: Choline deficiency, one main trigger for nonalcoholic fatty liver disease (NAFLD), is closely related to lipid metabolism disorder. Previous study in a choline-deficient model has largely focused on gene expression rather than gene structure, especially sparse are studies regarding to alternative splicing (AS). In modern life science research, primary hepatocytes culture technology facilitates such studies, which can accurately imitate liver activity <i>in vitro</i> and show unique superiority. Whereas limitations to traditional hepatocytes culture technology exist in terms of efficiency and operability. This study pursued an optimization culture method for duck primary hepatocytes to explore AS in choline-deficient model.Methods: We performed an optimization culture method for duck primary hepatocytes with multi-step digestion procedure from Pekin duck embryos. Subsequently a NAFLD model was constructed with choline-free medium. RNA-seq and further analysis by rMATS were performed to identify AS events alterations in choline-deficency duck primary hepatocytes.Results: The results showed E13 (embryonic day 13) to E15 is suitable to obtain hepatocytes, and the viability reached over 95% by trypan blue exclusion assay. Primary hepatocyte retained their biological function as well identified by Periodic Acid-Schiff staining method and Glucose-6-phosphate dehydrogenase activity assay, respectively. Meanwhile, genes of <i>alb</i> and <i>afp</i> and specific protein of albumin were detected to verify cultured hepatocytes. Immunofluorescence was used to evaluate purity of hepatocytes, presenting up to 90%. On this base, choline-deficient model was constructed and displayed significantly increase of intracellular triglyceride and cholesterol as reported previously. Intriguingly, our data suggested that AS events in choline-deficient model were implicated in pivotal biological processes as an aberrant transcriptional regulator, of which 16 genes were involved in lipid metabolism and highly enriched in glycerophospholipid metabolism.Conclusion: An effective and rapid protocol for obtaining duck primary hepatocytes was established, by which our findings manifested choline deficiency could induce the accumulation of lipid and result in aberrant AS events in hepatocytes, providing a novel insight into various AS in the metabolism role of choline.

Protection Relay and Fault Information Analyzing System for Smart Grid

Ge, Liang,Wang, Liding,Yang, Changfu,Zhou, Shuxiong 대한전기학회 2013 The Journal of International Council on Electrical Vol.3 No.2

For smart grid, the fault information from protection relays and fault recorders is useful for dispatchers to identify the grid fault and resume the power supply fleetly when a fault occurs. Traditionally, EMS/SCADA doesn't have the ability to collect the fault information. An application of protection relay and fault information analyzing system is proposed. In order to implement smarter analyzing functions, three approaches are adopted. First, the system unifies IEC61850 and IEC103 for modeling. Second, an analyzing method of relay characteristic is proposed to evaluate the action behavior of protection relays. Finally, the paper presents an approach to replay the actual action sequence with relay's logic diagram. The system has been carried out and the paper concludes that the system is effective and useful for dispatchers and relay operators in smart grid.