Investigations into film cooling and unsteady flow characteristics in a blade trailing-edge cutback region

Yan Gao,Xin Yan,Jun Li,Kun He 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.10

Unsteady flow characteristic and film cooling effect in the blade trailing edge cutback region are numerically investigated using DES (detached eddy simulation) method at three blowing ratios, four lip thickness ratios and three rib geometries. With the experimental data, reliability and accuracy of the numerical methods are validated. The results indicate that, compared with RANS (Reynolds-averaged Navier-Stokes) equations solutions, the DES method has a superior accuracy in predicting the film cooling effectiveness on trailing-edge cutback. The lip thickness has a pronounced effect on shedding vortex scale downstream the slot. As the lip thickness ratio decreases, the film cooling effect on trailing edge cutback is improved. Compared with the line ribs, the arrangement of pin fin ribs enhances the uniformity of coolant coverage on trailing edge cutback along lateral direction. However, with different types of rib, the film cooling effectiveness on the trailing edge cutback is mainly determined by the stable cooling flow structures and mixing effect between mainstream and coolant. The development of vortex system downstream the slot is significantly affected by the blowing ratio, which in turn influences the film cooling effect on trailing edge cutback.

Interval Observer-based Robust Trajectory Tracking Control for Quadrotor Unmanned Aerial Vehicle

Kun Yan,Jing-Rong Zhang,Hai-Peng Ren 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.1

In this work, a robust trajectory tracking control strategy is developed for the quadrotor unmanned aerial vehicle (QUAV) with unknown external disturbance. The nonlinear dynamic model of QUAV is established. Different from the traditional disturbance observer and adaptive estimation method, this paper adopts the interval observer technique to approximate the upper and lower bounds of the unknown disturbance. In this way, the proposed interval observer can cover its all possible values and show its scope in real time, especially before the disturbance error estimation converges. Combining with the backstepping approach, a robust tracking control approach is proposed to ensure that the desired trajectory can be successfully followed. Finally, comparative numerical simulation results are provided to evaluate the presented robust tracking controller.

Current Status of Indoor Positioning System Based on Visible Light

Kun Yan,Haiyan Zhou,Hailin Xiao,Xiangli Zhang 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10

With the flourishing of wireless information access, indoor positioning is becoming a topic of interest in both academic and industry community. Numerous techniques have been proposed to address this problem under diverse circumstances. Recently, the area of indoor positioning is dominated by three kinds of methodologies, such as rangebased positioning, fingerprint-based positioning and inertial positioning. This paper is presented to overview the indoor positioning techniques using visible light based on the range-based positioning. The state-of-the-art research results will be studied. The typical localization mechanisms used in visible light positioning systems are analyzed by evaluation metrics to provide an insight of the systems’ performances.

Making Sight Translation Dynamic : Eliciting Summarization as a Strategy for Simultaneous Interpretation

Kun Yan,Zhongwei Song 이화여자대학교 통역번역연구소 2021 T&I review Vol.11 No.2

Focusing on the specific exercise intended for eliciting summarization strategy to mitigate content omission for novice SI trainees, this article captures and analyses relevant longitudinal data from an action research conducted to investigate the extent to which sight translation (ST) facilitates skill development and transfer for simultaneous interpreting (SI) and to explore what specific strategies novice SI students could elicit from doing a dynamic type of sight translation (DST). Based on the action research conducted with three groups of student participants enrolled in Master of Conference Interpreting Program, a one-year program in 2014, 2015 and 2016 respectively, this article specifically reports the actions in eliciting the strategy of summarization via DST exercise and examines how the students responded to such a new teaching tool in a teaching environment. While the finding confirms that the progression from declarative knowledge to procedural knowledge takes time, it also supports that DST can be a useful driver of skill development and strategy application for novice interpreters at the beginning of conference interpreting training due to its similarities to SI.

Chinese international students in the United States: demographic trends, motivations, acculturation features and adjustment challenges

Kun Yan,David C. Berliner 서울대학교 교육연구소 2011 Asia Pacific Education Review Vol.12 No.2

To date, few studies have focused solely upon understanding the unique characteristics of Chinese international students in the United States. This inquiry examines what Chinese international students' demographic trends are over decades, what their motivations are for studying in the United States, what the unique features of their group acculturation process are, and what special challenges they face in U.S. universities that are different from what they might face in Chinese universities? This study reveals that the life of Chinese students in the United States is not easy and they have to endure multifaceted life-stresses. These results can be used to help Chinese international students adapt to the American educational environment and improve the services and programs American universities deliver to their foreign students.

Tensions in gifted college programs in China: the case of “Mount Everest Plan”

Kun Yan,David C. Berliner 서울대학교 교육연구소 2016 Asia Pacific Education Review Vol.17 No.2

To date, no empirical study has focused upon understanding the tensions in gifted college programs in China. This qualitative inquiry examines the tensions the “Mount Everest Plan” programs face while initiating gifted education reform in China, how the gifted college students characterize these tensions, and what conditions they believe tend to account for the tensions. The voices of 18 gifted college students were heard through individual semi-structured interviews and the transcripts of the interviews were analyzed using thematic coding to uncover the themes related to the tensions. This qualitative case study identifies multiple tensions arise surrounding the “Mount Everest Plan” programs which include program training needs versus students’ personal growth needs, program identification purposes versus students’ personal motives, identification of a person versus identification of a path to success, and high variance within the gifted class versus undifferentiated curriculum. These tensions involve competing arguments on the genesis and the development of gifted education and gifted students. The study also discusses possible ways of resolving and easing these tensions so that the services and programs can be enhanced.

Hookworm Infection: A Neglected Cause of Overt Obscure Gastrointestinal Bleeding

Kun-Yan Wei,Qiong Yan,Bo Tang,Shi-Ming Yang,Peng-Bing Zhang,Ming-Ming Deng,Mu-Han Lu 대한기생충학열대의학회 2017 The Korean Journal of Parasitology Vol.55 No.4

Two New α-Pyrones and Other Components from the Cladodes of Opuntia dillenii

Ying Kun Qiu,Yan Yan Zhao,De Qiang Dou,Bi Xia Xu,Ke Liu 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.6

The aqueous ethanolic extract from the fresh cladodes of Opuntia dillenii HAW. was found to show anti-inflammatory activity. Two new α-pyrones, named opuntioside II (1) and opuntioside III (2), were isolated from the extract together with six known compounds. The structures of the new compounds were determined on the basis of chemical and physicochemical evidence.

체육시설 지도자들이 지각하는 감정표현규범과 감정노동, 감정고갈 및 이직의도와의 관계

왕곤염(Wang, Kun-Yan),황지현(Hwang, Ji-Hyun) 한국체육과학회 2018 한국체육과학회지 Vol.27 No.6

This study aims to identify the relationship between the norm of emotion expression of the coaches working at sports facilities and emotional labor, exhaustion of emotion and the intention to change jobs. The objects of research are the 230 coaches working at sports facilities located in Seoul Metropolitan City and Gyeonggi–do Province. For the verification of the hypotheses established in this study, frequency analysis, exploratory factor analysis, reliability analysis, confirmatory factor analysis and structure equation model analysis were conducted with PASW 18.0 and AMOS 18.0 data processing programs. The following are the results of the analyses. Firstly, the norm of emotion expression has meaningful influence on the surface behavior and the internal behavior that are the sub factors of emotional labor. Secondly, while the surface behavior, which is a sub factor of emotional labor, has meaningful influence on exhaustion of emotion, it does not have influence on internal behavior. Thirdly, exhaustion of emotion has meaning influence on the intention to change jobs.

피트니스 센터 기관장의 서번트 리더십이 지도자의 셀프리더십에 미치는 영향

왕곤염(Wang, Kun-Yan),황지현(Hwang, Ji-Hyun) 한국체육과학회 2018 한국체육과학회지 Vol.27 No.6

This study`s objective is to examine the influence of the fitness center chief`s servant leadership on the trainer`s self-leadership. To achieve this objective, 213 trainers from 30 fitness centers were surveyed. The documented surveys filled out by the subjects were collected and processed statistically for research purpose. Questionnaire was used as the measurement tool. The questionnaire had a total of 30 questions consisting of 4 social demographic questions, 10 servant leadership questions, and 16 self-leadership questions. For verification, 5% was the set significance level and a statistical program was used to analyze the correlation between the fitness center chief"s servant leadership and the trainer`s self-leadership and conduct multiple regression analysis. The deducted conclusion is the following. First, the chief`s servant leadership affected the constructive thinking strategy of the trainer`s self-leadership. Second, the chief`s servant leadership affected the natural reward strategy of the trainer`s self-leadership. Third, the chief`s servant leadership affected the behavior focused strategy of the trainer`s self-leadership.