An update algorithm design using moving Region of Attraction for SDRE based control law     

Engin H. Copur  Ahmet C. Arican  Sinan Ozcan  Metin U. Salamci 《Journal of The Franklin Institute》2019,356(15):8388-8413

State Dependent Riccati Equation (SDRE) methods have the considerable advantages over other nonlinear control methods. However, stability issues can be arisen in SDRE based control system due to the lack of the global asymptotic stability property. Therefore, the previous studies have usually shown that local asymptotic stability can be ensured by estimating a Region of Attraction (ROA) around the equilibrium point. These estimated regions for stability may become narrow or the condition to keep the states in this region may be very conservative. To resolve these issues, this paper proposes a novel SDRE method employing an update algorithm to re-estimate the ROA when the states tend to move out of the stable region. The tendency is checked using a condition which is developed based on a new theorem. The theorem proves that it is possible to redesign the previous ROA with respect to the current states lying close to its boundary for ensuring the “non-local” stability along the trajectory without the need of solving SDRE at each time instant, unlike the standard SDRE approach. Therefore, the new theorem is now able to enhance the stability of the SDRE based closed-loop control system. The feasibility of the proposed SDRE control method is tested in both simulations and experiments. A validated 3-DOF laboratory helicopter is used for experiments and the control objective for the helicopter is to realise a preplanned movement in both elevation and travel axes. The results reveal that the proposed SDRE approach enables the controlled plant to track the desired trajectory as satisfactorily as the standard SDRE approach, while only solving SDRE when needed. The proposed SDRE method reduces the computational load for practical implementation of the control algorithm whilst ensuring the stability over the operational region.  相似文献   

新疆双语教育跨越式发展的问题与对策研究     

艾合买提·艾买提  顾华详 《民族教育研究》2011,22(6)

双语教育是发展新疆民族教育事业的一项战略措施.要适应新疆跨越式发展和长治久安战略实施的需要,推进双语教育跨越式发展,必须切实提高科学推进少数民族学前和中小学双语教育政策的执行力度,坚持采取多种有效措施,加强高素质双语教师队伍建设;健全双语教师评价和激励机制,吸引大批优秀人才从事双语教育工作;高度重视双语教育的科学研究工作,强化对教学实践的指导作用;充分有效地发挥现代远程教育设备在双语教学中的作用,重视发挥民汉合校和集中办学规模优势,大面积提高双语教育质量;坚持以传承中华文化为核心,高度重视文化交流交融,促进各民族之间的相互理解与认同.  相似文献   

Determination and Evaluation of the Science Teacher Candidates’ Misconceptions About Density by Using Four-Tier Diagnostic Test     

Kiray  Seyit Ahmet  Simsek  Sena 《International Journal of Science and Mathematics Education》2021,19(5):935-955

This study has two aims. The first one is to reveal the science teacher candidates’ misconceptions about the density by using a four-tier diagnostic test, and the second one is to determine to what extent science teacher candidates have scientific knowledge, lack of knowledge, and misconceptions about the density. In order to achieve these aims, a four-tier density diagnostic test was developed with the KR-20 reliability coefficient of 0.753 based on the correct answers, and the KR-20 reliability coefficient of 0.528 based on the misconceptions. To determine the misconceptions about the density with the developed test, data were collected from a total of 470 science teacher candidates from seven different universities in Turkey. With the developed four-tier diagnostic test, 48 different misconceptions were revealed. The results of the research showed that about one fourth of science teacher candidates had a misconception about the density and that the ratio of six of the resulting misconceptions was over 10%. It may be suggested that this study conducted on science teacher candidates should also be conducted on middle and high school students and experimental studies should be carried out to eliminate the misconceptions that emerged in this study.

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The mediating roles of internal context variables in the relationship between distributed leadership perceptions and continuous change behaviours of public school teachers     

Yaşar Kondakci  Merve Zayim  Kadir Beycioglu  Mehmet Sincar  Celal T Ugurlu 《Educational studies》2016,42(4):410-426

This study aims at building a theoretical base for continuous change in education and using this base to test the mediating roles of two key contextual variables, knowledge sharing and trust, in the relationship between the distributed leadership perceptions and continuous change behaviours of teachers. Data were collected from 687 public school teachers. The results showed that the combined effect of knowledge sharing and faculty trust in principal mediated the relationship between teachers’ distributed leadership perceptions and continuous change behaviours. The directions of the coefficients of the relationships between the independent variable and the dependent variable suggested that higher distributed leadership perception leads to increased knowledge sharing and trust in principal, which in turn was associated with greater continuous change behaviours. The study showed that school systems have an extensive capacity for self-improvement, even in the absence of a pre-developed change plan.  相似文献   

Diffusion of distance education in Turkish higher education     

Aytekin Işman 《Educational technology research and development : ETR & D》1997,45(2):124-128

Conclusion In this paper, Rogers's diffusion theory was used to analyze the acceptance and implementation of the innovation of distance education in higher education in Turkey. Distance education was not successfully adopted between 1970 and 1980 in Turkey because of organizational problems. Distance education was effectively and efficiently diffused in Turkey after 1982. Thousands of students today earn university diplomas studying at a distance. On the other hand, problems of organization, technology, and perceptions remain to be addressed. It is to be hoped that in the future the OEF will be independent or have more autonomy. This will help it deliver instruction to its students.the evaluator of the Learning Community Link Project at the University.  相似文献   

Pre-service teachers’ cultural and teaching experiences abroad     

Armağan Ateşkan 《师资教育杂志》2016,42(2):135-148

This study investigates Turkish pre-service teachers’ experiences related to a two-month international teaching and cultural experience in the United States of America. In total, 289 graduate students from Turkey participated in a collaborative project from 2001 to 2010. The experience included an orientation week, six weeks of student teaching in a high school, seminars and projects at Iowa State University and cultural visits. The data were collected through a pre-service teacher questionnaire and their reflective journals. The results showed that pre-service teachers perceived the international teaching experience helped them develop professionally and personally. Through cross-cultural exchanges with their mentors along with other students and their community, the pre-service teachers expanded their knowledge of a new culture and adapted to a new working environment.  相似文献   

Crossing Paths: Intercultural Collaborations     

Ahmet Atay  Satoshi Toyosaki 《Communication Studies》2018,69(4):366-371

There are unusual elements in this essay. It is a coconstructed intercultural narrative about spaces, places, people, and ideas, about their influence on us and our academic journeys, separately and together. Each narrative considers the intercultural footpaths and bridges that have connected us to one another and to others in the Central States Communication Association (CSCA) and the Intercultural Communication (IC) interest group.  相似文献   

Introduction: Intercultural Studies within Central States     

Ahmet Atay  Alberto González 《Communication Studies》2018,69(4):337-340

The study of intercultural communication (IC) has a long history in the Central States Communication Association (CSCA). Some of the earliest work in IC has come from universities in the CSCA region, such as Indiana University (William Starosta) and University of Minnesota (Vernon Jensen and Rosita Albert). Since the inception of the Intercultural Communication Interest Group within CSCA in the early 1990s, IC scholars have contributed immensely to the discipline by studying different aspects of the relationship between communication and culture. Several active IC scholars present their recollections of the development of IC research in this issue.  相似文献   

Culture and education: looking back to culture through education     

Filiz Meşeci Giorgetti  Craig Campbell  Ali Arslan 《Paedagogica Historica: International Journal of the History of Education》2017,53(1-2):1-6

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Measuring the perceived quality of an AR-based learning application: a multidimensional model     

Costin Pribeanu  Alexandru Balog  Dragoş Daniel Iordache 《Interactive Learning Environments》2017,25(4):482-495

Augmented reality (AR) technologies could enhance learning in several ways. The quality of an AR-based educational platform is a combination of key features that manifests in usability, usefulness, and enjoyment for the learner. In this paper, we present a multidimensional model to measure the quality of an AR-based application as perceived by students. The model is specified by a second-order factor (perceived quality) and three dimensions: ergonomic quality, learning quality, and hedonic quality. The purpose of this model is to embody previous research into a coherent framework for the evaluation of AR-based educational platforms and to provide guidance for researchers and practitioners. The model was empirically validated on a Chemistry learning scenario and the results confirm the importance of both the learning and hedonic quality.  相似文献