Constrained Variational Policy Optimization for Emergency Load Shedding of Power Systems

Haotian Zhang,Xinfeng Sun,Myoung Hoon Lee,Jun Moon 제어로봇시스템학회 2023 제어로봇시스템학회 국내학술대회 논문집 Vol.2023 No.6

허우샤오셴 영화의 롱테이크 특징 분석 - 〈연연풍진〉를 중심으로-

장호천(ZHANG HAOTIAN) 한국엔터테인먼트산업학회 2022 한국엔터테인먼트산업학회 학술대회 논문집 Vol.2022 No.5

장비와 기술의 발전에 따라 점점 더 많은 영화가 숏 테이크 촬영 기법과 편집 효과에 주목하고 있다. 전 세계 박스오피스 집계에 따르면 박스오피스 상위 100편 중 90편이 숏 테이크 편집 위주로 제작되었음을 확인할 수 있다. 그러나 허우샤오셴 감독은 트렌드를 거스르는 촬영 기법을 고집하였고, 롱 테이크를 주요 촬영 기법으로 사용했다. 타 감독들은 영화 장르나 촬영 내용에 따라 선택적으로 롱 테이크를 사용하는 반면, 허우샤오셴은 영화 장면의 대부분을 롱 테이크로 촬영하며 그의 작품을 타 감독들의 작품과 차별화 시켰다. 이를 통해 그의 영화에서 롱 테이크 기법이 다른 기법으로 대체될 수 없는 독보적인 특징을 가진다는 것을 알 수 있다.이 글에서는 허우샤오시엔 감독의 영화 〈연연풍진〉을 선택하여 그 중 롱 테이크 활용에 대해 상세한 통계와 분석을 진행하여 허우샤오시엔 감독의 3가지 상용 롱 테이크 활용법을 얻어내였다. 또 〈연연풍진〉 이 영화에서 이런 세가지 롱 테이크 활용을 분석해 허우샤오시엔의 영화 속 롱 테이크의 특징을 얻어내였다. 그의 롱 테이크는 영화 속에서 단순히 시간의 연장이 아니라 공간과 시간, 정서에 대한 사실적 묘사임을 알 수 있다. Since the shooting equipment and technology has been developing, more and more films focus on various short shot shooting methods and editing effects. According to the global box office statistics, 90% of the top 100 films are mainly short shots and a large number of clips. Director Hsiao-hsien Hou, however, is contrary to the trend, whose films adopt a lot of long take, which becomes his characteristic. Other directors may need to use long take in a film on the basis of the subject matter or content of the film, while Hsiao-hsien Hou"s entire film is full of long take, which is completely different from other directors" practice, indicating that long take have irreplaceable characteristics in his films and it is important to analyze the characteristics of his long take. Therefore, out of curiosity about the long take in Hsiao-hsien Hou"s films, I started this research to explore what makes Hsiao-hsien Hou so obsessed with long take. This paper takes Hsiao-hsien Hou"s film 〈Dust in the Wind〉 as the research subject, conducting the detailed statistics and analysis to the long take use among them, to obtain Hsiao-hsien Hou director"s three commonly used long take use method, and summarizes the characteristics of long take in Hsiao-hsien Hou"s film, by analyzing the use of these three kinds of long take in this film. It is found that his long take in the film is not simply to prolong the time, but to describe space, time and emotion.

Study on seismic performance of connection joint between prefabricated prestressed concrete beams and high strength reinforcement-confined concrete columns

Haotian Jiang,Qingning Li,Weishan Jiang,De-Yi Zhang 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.21 No.2

As the common cast-in-place construction works fails to meet the enormous construction demand under rapid economic growth, the development of prefabricated structure instead becomes increasingly promising in China. For the prefabricated structure, its load carrying connection joint play a key role in maintaining the structural integrity. Therefore, a novel end plate bolt connecting joint between fully prefabricated pre-stressed concrete beam and highstrength reinforcement-confined concrete column was proposed. Under action of low cycle repeated horizontal loadings, comparative tests are conducted on 6 prefabricated pre-stressed intermediate joint specimens and 1 cast-inplace joint specimen to obtain the specimen failure modes, hysteresis curves, skeleton curves, ductility factor, stiffness degradation and energy dissipation capacity and other seismic indicators, and the seismic characteristics of the new-type prefabricated beam-column connecting joint are determined. The test results show that all the specimens for end plate bolt connecting joint between fully prefabricated pre-stressed concrete beam and highstrength reinforcement-confined concrete column have realized the design objectives of strong column weak beam. The hysteretic curves for specimens are good, indicating desirable ductility and energy dissipation capacity and seismic performances, and the research results provide theoretical basis and technical support for the promotion and application of prefabricated assembly frames in the earthquake zone.

Experimental study on a new type of assembly bolted end-plate connection

Shufeng Li,Qingning Li,Haotian Jiang,Hao Zhang,Lei Yan,Weishan Jiang 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.26 No.4

The bolted end-plate beam-column connections have been widely used in steel structure and composite structure because of its excellent seismic performance. In this paper, the end-plate bolted connection is applied in the concrete structure, A new-type of fabricated beam-column connections with end-plates is presented, and steel plate hoop is used to replace stirrups in the node core area. To study the seismic behavior of the joint, seven specimens are tested by pseudo-static test. The experimental results show that the new type of assembly node has good ductility and energy dissipation capacity. Besides, under the restraint effect of the high-strength stirrup, the width of the web crack is effectively controlled. In addition, based on the analysis of the factors affecting the shear capacity of the node core area, the formula of shear capacity of the core area of the node is proposed, and the theoretical values of the formula are consistent with the experimental value.

Distributed Secondary Control of AC Microgrid and its Frequency Domain Analysis Considering Time Delay

Cheng Zhiping,Wang Kaifang,Li Zhongwen,Wu Haotian,Zhi Changyi,Zhang Jinbin 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.1

In this paper, distributed secondary control of AC microgrid (MG) is studied and the infuence of communication delay on its control performance is analyzed and verifed. Firstly, a secondary control strategy for the MG is designed to achieve frequency recovery and proportional active power dispatch. Secondly, the stability of the MG system is analyzed in the frequency domain and a rigorous formula is derived to calculate the delay margin for the stability of the distributed secondary control with communication delays. The theoretical calculation results of the stability margin are approximately consistent with the simulation results, with an error of only 1.27%. The efects of the algorithm gains, communication topology, and connection weights on the delay margin are discussed based on the derived formula. The results demonstrate that the algorithm gain is inversely proportional to the delay margin. Changes in the communication topology and connection weights lead to changes in the maximum eigenvalue of the adjacency matrix L, which in turn afects the delay margin. Moreover, the infuence of time-varying delays is considered. The system can tolerate greater time-varying delays than fxed delays. Simulation and experimental results validate the efectiveness and feasibility of the proposed method.

Experimental study on ultrasonic-assisted grinding of micro-structured surface on silicon carbide using small diameter grinding wheel

Hongbo Li,Tao Chen,Zhenyan Duan,Yiwen Zhang,Haotian Li 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.7

As an effective machining method for hard and brittle materials, ultrasonicassisted grinding (UAG) was employed to manufacture microstructures on SiC in this study. The kinematic characteristics of abrasive grains during machining were analyzed first. After that, the influence of machining parameters on the shape accuracy and surface quality was revealed experimentally. The results demonstrate that the feed rate and ultrasonic amplitude have significant effects on machining quality. The introduction of ultrasonic vibration can effectively reduce the grinding force and improve the surface finish quality. For the micro cylinder array, by selecting the ultrasonic amplitude rationally, the peak-to-valley (PV) value and surface roughness can be decreased by 15.8 % and 27.5 %. Furthermore, microcracks, dominated by lateral cracks and fractures were found on the sub-surface. Compared with conventional grinding, UAG can reduce the subsurface damage (SSD) depth and gain a more uniform distribution of damage regions along the machined surface.