WorldWideScience

Sample records for satellite-based synchronous tutorials

  1. Face-to-face talk and synchronous chat as learning tools in tutorial ...

    African Journals Online (AJOL)

    The findings suggest that although synchronous chat and small-group discussion share certain characteristics, they are also distinct in several significant ways. The implications that these differences hold for language instruction are then discussed. Keywords: synchronous CMC, tutorials, CLT, group work, blended learning, ...

  2. Simulation and Analysis of Autonomous Time Synchronization Based on Asynchronism Two-way Inter-satellite Link

    Science.gov (United States)

    Fang, L.; Yang, X. H.; Sun, B. Q.; Qin, W. J.; Kong, Y.

    2013-09-01

    The measurement of the inter-satellite link is one of the key techniques in the autonomous operation of satellite navigation system. Based on the asynchronism inter-satellite two-way measurement mode in GPS constellation, the reduction formula of the inter-satellite time synchronization is built in this paper. Moreover, the corrective method of main systematic errors is proposed. Inter-satellite two-way time synchronization is simulated on the basis of IGS (International GNSS Service) precise ephemeris. The impacts of the epoch domestication of asynchronism inter-satellite link pseudo-range, the initial orbit, and the main systematic errors on satellite time synchronization are analyzed. Furthermore, the broadcast clock error of each satellite is calculated by the ``centralized'' inter-satellite autonomous time synchronization. Simulation results show that the epoch domestication of asynchronism inter-satellite link pseudo-range and the initial orbit have little impact on the satellite clock errors, and thus they needn't be taken into account. The errors caused by the relativistic effect and the asymmetry of path travel have large impact on the satellite clock errors. These should be corrected with theoretical formula. Compared with the IGS precise clock error, the root mean square of the broadcast clock error of each satellite is about 0.4 ns.

  3. Tutorial chat: a case study of synchronous communication in a learning environment

    Directory of Open Access Journals (Sweden)

    Malcolm Rutter

    2006-12-01

    Full Text Available This case study describes the use of a web-based synchronous chat application, run during computing tutorials. The chat room was moderated by a paid demonstrator, who assisted and encouraged students whenever possible. Most of the discussion was banter, which acted as a lubricant for relevant factual communication. Students were permitted a degree of anonymity, but nevertheless learned to treat the facility in a useful manner. The application and its mode of employment were found to be both motivating and supportive. Use was evaluated by questionnaire and an analysis of student input. As a result of the experience, it is suggested that abuse will certainly occur and may be minimised by technical improvements, but never eliminated. The Rogerian approach adopted was found to have transferred emphasis from teaching a topic to the learning of generic skills.

  4. A satellite mobile communication system based on Band-Limited Quasi-Synchronous Code Division Multiple Access (BLQS-CDMA)

    Science.gov (United States)

    Degaudenzi, R.; Elia, C.; Viola, R.

    1990-01-01

    Discussed here is a new approach to code division multiple access applied to a mobile system for voice (and data) services based on Band Limited Quasi Synchronous Code Division Multiple Access (BLQS-CDMA). The system requires users to be chip synchronized to reduce the contribution of self-interference and to make use of voice activation in order to increase the satellite power efficiency. In order to achieve spectral efficiency, Nyquist chip pulse shaping is used with no detection performance impairment. The synchronization problems are solved in the forward link by distributing a master code, whereas carrier forced activation and closed loop control techniques have been adopted in the return link. System performance sensitivity to nonlinear amplification and timing/frequency synchronization errors are analyzed.

  5. Making generic tutorials content specific: recycling evidence-based practice (EBP) tutorials for two disciplines.

    Science.gov (United States)

    Jeffery, Keven M; Maggio, Lauren; Blanchard, Mary

    2009-01-01

    Librarians at the Boston University Medical Center constructed two interactive online tutorials, "Introduction to EBM" and "Formulating a Clinical Question (PICO)," for a Family Medicine Clerkship and then quickly repurposed the existing tutorials to support an Evidence-based Dentistry course. Adobe's ColdFusion software was used to populate the tutorials with course-specific content based on the URL used to enter each tutorial, and a MySQL database was used to collect student input. Student responses were viewable immediately by course faculty on a password-protected Web site. The tutorials ensured that all students received the same baseline training and allowed librarians to tailor a subsequent library skills workshop to student tutorial answers. The tutorials were well-received by the medical and dental schools and have been added to mandatory first-year Evidence-based Medicine (EBM) and Evidence-based Dentistry (EBD) courses, meaning that every medical and dental student at BUMC will be expected to complete these tutorials.

  6. The synchronization method for distributed small satellite SAR

    Science.gov (United States)

    Xing, Lei; Gong, Xiaochun; Qiu, Wenxun; Sun, Zhaowei

    2007-11-01

    One of critical requirement for distributed small satellite SAR is the trigger time precision when all satellites turning on radar loads. This trigger operation is controlled by a dedicated communication tool or GPS system. In this paper a hardware platform is proposed which has integrated navigation, attitude control, and data handling system together. Based on it, a probabilistic synchronization method is proposed for SAR time precision requirement with ring architecture. To simplify design of transceiver, half-duplex communication way is used in this method. Research shows that time precision is relevant to relative frequency drift rate, satellite number, retry times, read error and round delay length. Installed with crystal oscillator short-term stability 10 -11 magnitude, this platform can achieve and maintain nanosecond order time error with a typical three satellites formation experiment during whole operating process.

  7. Synchronous atmospheric radiation correction of GF-2 satellite multispectral image

    Science.gov (United States)

    Bian, Fuqiang; Fan, Dongdong; Zhang, Yan; Wang, Dandan

    2018-02-01

    GF-2 remote sensing products have been widely used in many fields for its high-quality information, which provides technical support for the the macroeconomic decisions. Atmospheric correction is the necessary part in the data preprocessing of the quantitative high resolution remote sensing, which can eliminate the signal interference in the radiation path caused by atmospheric scattering and absorption, and reducting apparent reflectance into real reflectance of the surface targets. Aiming at the problem that current research lack of atmospheric date which are synchronization and region matching of the surface observation image, this research utilize the MODIS Level 1B synchronous data to simulate synchronized atmospheric condition, and write programs to implementation process of aerosol retrieval and atmospheric correction, then generate a lookup table of the remote sensing image based on the radioactive transfer model of 6S (second simulation of a satellite signal in the solar spectrum) to correct the atmospheric effect of multispectral image from GF-2 satellite PMS-1 payload. According to the correction results, this paper analyzes the pixel histogram of the reflectance spectrum of the 4 spectral bands of PMS-1, and evaluates the correction results of different spectral bands. Then conducted a comparison experiment on the same GF-2 image based on the QUAC. According to the different targets respectively statistics the average value of NDVI, implement a comparative study of NDVI from two different results. The degree of influence was discussed by whether to adopt synchronous atmospheric date. The study shows that the result of the synchronous atmospheric parameters have significantly improved the quantitative application of the GF-2 remote sensing data.

  8. New GOES satellite synchronized time code generation

    Science.gov (United States)

    Fossler, D. E.; Olson, R. K.

    1984-01-01

    The TRAK Systems' GOES Satellite Synchronized Time Code Generator is described. TRAK Systems has developed this timing instrument to supply improved accuracy over most existing GOES receiver clocks. A classical time code generator is integrated with a GOES receiver.

  9. An Autonomous Satellite Time Synchronization System Using Remotely Disciplined VC-OCXOs

    Directory of Open Access Journals (Sweden)

    Xiaobo Gu

    2015-07-01

    Full Text Available An autonomous remote clock control system is proposed to provide time synchronization and frequency syntonization for satellite to satellite or ground to satellite time transfer, with the system comprising on-board voltage controlled oven controlled crystal oscillators (VC-OCXOs that are disciplined to a remote master atomic clock or oscillator. The synchronization loop aims to provide autonomous operation over extended periods, be widely applicable to a variety of scenarios and robust. A new architecture comprising the use of frequency division duplex (FDD, synchronous time division (STDD duplex and code division multiple access (CDMA with a centralized topology is employed. This new design utilizes dual one-way ranging methods to precisely measure the clock error, adopts least square (LS methods to predict the clock error and employs a third-order phase lock loop (PLL to generate the voltage control signal. A general functional model for this system is proposed and the error sources and delays that affect the time synchronization are discussed. Related algorithms for estimating and correcting these errors are also proposed. The performance of the proposed system is simulated and guidance for selecting the clock is provided.

  10. Interaction Patterns in Synchronous Chinese Tutorials

    Science.gov (United States)

    Shi, Lijing; Stickler, Ursula

    2018-01-01

    Speaking in Chinese is problematic for all learners, particularly for beginners and more so during online interaction. Despite the fact that interaction has been identified as crucial for the development of speaking skills, it can be hindered by students' lack of language competence or their anxiety. Teacher-centred practices in tutorials can…

  11. Remote atomic clock synchronization via satellites and optical fibers

    OpenAIRE

    Piester, D.; Rost, M.; Fujieda, M.; Feldmann, T.; Bauch, A.

    2011-01-01

    In the global network of institutions engaged with the realization of International Atomic Time (TAI), atomic clocks and time scales are compared by means of the Global Positioning System (GPS) and by employing telecommunication satellites for two-way satellite time and frequency transfer (TWSTFT). The frequencies of the state-of-the-art primary caesium fountain clocks can be compared at the level of 10−15 (relative, 1 day averaging) and time scales can be synchronized...

  12. Establishing and maintaining a satellite campus connected by synchronous video conferencing.

    Science.gov (United States)

    Fox, Brent I; McDonough, Sharon L; McConatha, Barry J; Marlowe, Karen F

    2011-06-10

    Pharmacy education has experienced substantial growth in the number of new schools and existing schools establishing satellite campuses. Several models have previously been used to connect primary and satellite campuses. We describe the Auburn University Harrison School of Pharmacy's (AUHSOP's) experiences using synchronous video conferencing between the Auburn University campus in Auburn and a satellite campus in Mobile, Alabama. We focus on the technology considerations related to planning, construction, implementation, and continued use of the various resources that support our program. Students' perceptions of their experiences related to technology also are described.

  13. Online Pedagogical Tutorial Tactics Optimization Using Genetic-Based Reinforcement Learning.

    Science.gov (United States)

    Lin, Hsuan-Ta; Lee, Po-Ming; Hsiao, Tzu-Chien

    2015-01-01

    Tutorial tactics are policies for an Intelligent Tutoring System (ITS) to decide the next action when there are multiple actions available. Recent research has demonstrated that when the learning contents were controlled so as to be the same, different tutorial tactics would make difference in students' learning gains. However, the Reinforcement Learning (RL) techniques that were used in previous studies to induce tutorial tactics are insufficient when encountering large problems and hence were used in offline manners. Therefore, we introduced a Genetic-Based Reinforcement Learning (GBML) approach to induce tutorial tactics in an online-learning manner without basing on any preexisting dataset. The introduced method can learn a set of rules from the environment in a manner similar to RL. It includes a genetic-based optimizer for rule discovery task by generating new rules from the old ones. This increases the scalability of a RL learner for larger problems. The results support our hypothesis about the capability of the GBML method to induce tutorial tactics. This suggests that the GBML method should be favorable in developing real-world ITS applications in the domain of tutorial tactics induction.

  14. Evaluating the role of web-based tutorials in educational practice

    DEFF Research Database (Denmark)

    Moring, Camilla; Schreiber, Trine

    The paper describes and discusses a two step analysis for evaluating web based information literacy tutorials in educational practice. In a recent evaluation project the authors used the analysis to examine three web based tutorials developed by three different academic libraries in Norway. Firstly...... of the analysis focuses on user reception and meaning negotiation. In combination the two different analyses strengthen the evaluation of how web-tutorials as communicative acts become meaningful to users, and how this meaning is negotiated in relation to an educational practice. This approach can be recommended...

  15. Prognostics 101: A tutorial for particle filter-based prognostics algorithm using Matlab

    International Nuclear Information System (INIS)

    An, Dawn; Choi, Joo-Ho; Kim, Nam Ho

    2013-01-01

    This paper presents a Matlab-based tutorial for model-based prognostics, which combines a physical model with observed data to identify model parameters, from which the remaining useful life (RUL) can be predicted. Among many model-based prognostics algorithms, the particle filter is used in this tutorial for parameter estimation of damage or a degradation model. The tutorial is presented using a Matlab script with 62 lines, including detailed explanations. As examples, a battery degradation model and a crack growth model are used to explain the updating process of model parameters, damage progression, and RUL prediction. In order to illustrate the results, the RUL at an arbitrary cycle are predicted in the form of distribution along with the median and 90% prediction interval. This tutorial will be helpful for the beginners in prognostics to understand and use the prognostics method, and we hope it provides a standard of particle filter based prognostics. -- Highlights: ► Matlab-based tutorial for model-based prognostics is presented. ► A battery degradation model and a crack growth model are used as examples. ► The RUL at an arbitrary cycle are predicted using the particle filter

  16. A Web-Based Comparative Genomics Tutorial for Investigating Microbial Genomes

    Directory of Open Access Journals (Sweden)

    Michael Strong

    2009-12-01

    Full Text Available As the number of completely sequenced microbial genomes continues to rise at an impressive rate, it is important to prepare students with the skills necessary to investigate microorganisms at the genomic level. As a part of the core curriculum for first-year graduate students in the biological sciences, we have implemented a web-based tutorial to introduce students to the fields of comparative and functional genomics. The tutorial focuses on recent computational methods for identifying functionally linked genes and proteins on a genome-wide scale and was used to introduce students to the Rosetta Stone, Phylogenetic Profile, conserved Gene Neighbor, and Operon computational methods. Students learned to use a number of publicly available web servers and databases to identify functionally linked genes in the Escherichia coli genome, with emphasis on genome organization and operon structure. The overall effectiveness of the tutorial was assessed based on student evaluations and homework assignments. The tutorial is available to other educators at http://www.doe-mbi.ucla.edu/~strong/m253.php.

  17. Content-based intermedia synchronization

    Science.gov (United States)

    Oh, Dong-Young; Sampath-Kumar, Srihari; Rangan, P. Venkat

    1995-03-01

    Inter-media synchronization methods developed until now have been based on syntactic timestamping of video frames and audio samples. These methods are not fully appropriate for the synchronization of multimedia objects which may have to be accessed individually by their contents, e.g. content-base data retrieval. We propose a content-based multimedia synchronization scheme in which a media stream is viewed as hierarchial composition of smaller objects which are logically structured based on the contents, and the synchronization is achieved by deriving temporal relations among logical units of media object. content-based synchronization offers several advantages such as, elimination of the need for time stamping, freedom from limitations of jitter, synchronization of independently captured media objects in video editing, and compensation for inherent asynchronies in capture times of video and audio.

  18. GPS-based satellite tracking system for precise positioning

    Science.gov (United States)

    Yunck, T. P.; Melbourne, W. G.; Thornton, C. L.

    1985-01-01

    NASA is developing a Global Positioning System (GPS) based measurement system to provide precise determination of earth satellite orbits, geodetic baselines, ionospheric electron content, and clock offsets between worldwide tracking sites. The system will employ variations on the differential GPS observing technique and will use a network of nine fixed ground terminals. Satellite applications will require either a GPS flight receiver or an on-board GPS beacon. Operation of the system for all but satellite tracking will begin by 1988. The first major satellite application will be a demonstration of decimeter accuracy in determining the altitude of TOPEX in the early 1990's. By then the system is expected to yield long-baseline accuracies of a few centimeters and instantaneous time synchronization to 1 ns.

  19. Fuzzy Control Tutorial

    DEFF Research Database (Denmark)

    Dotoli, M.; Jantzen, Jan

    1999-01-01

    The tutorial concerns automatic control of an inverted pendulum, especially rule based control by means of fuzzy logic. A ball balancer, implemented in a software simulator in Matlab, is used as a practical case study. The objectives of the tutorial are to teach the basics of fuzzy control......, and to show how to apply fuzzy logic in automatic control. The tutorial is distance learning, where students interact one-to-one with the teacher using e-mail....

  20. IL web tutorials

    DEFF Research Database (Denmark)

    Hyldegård, Jette; Lund, Haakon

    2012-01-01

    The paper presents the results from a study on information literacy in a higher education (HE) context based on a larger research project evaluating 3 Norwegian IL web tutorials at 6 universities and colleges in Norway. The aim was to evaluate how the 3 web tutorials served students’ information...... seeking and writing process in an study context and to identify barriers to the employment and use of the IL web tutorials, hence to the underlying information literacy intentions by the developer. Both qualitative and quantitative methods were employed. A clear mismatch was found between intention...... and use of the web tutorials. In addition, usability only played a minor role compared to relevance. It is concluded that the positive expectations of the IL web tutorials tend to be overrated by the developers. Suggestions for further research are presented....

  1. Assessing the Effectiveness of Web-Based Tutorials Using Pre-and Post-Test Measurements

    Science.gov (United States)

    Guy, Retta Sweat; Lownes-Jackson, Millicent

    2012-01-01

    Computer technology in general and the Internet in particular have facilitated as well as motivated the development of Web-based tutorials (MacKinnon & Williams, 2006). The current research study describes a pedagogical approach that exploits the use of self-paced, Web-based tutorials for assisting students with reviewing grammar and mechanics…

  2. Gigabit Satellite Network for NASA's Advanced Communication Technology Satellite (ACTS)

    Science.gov (United States)

    Hoder, Douglas; Bergamo, Marcos

    1996-01-01

    The advanced communication technology satellite (ACTS) gigabit satellite network provides long-haul point-to-point and point-to-multipoint full-duplex SONET services over NASA's ACTS. at rates up to 622 Mbit/s (SONET OC-12), with signal quality comparable to that obtained with terrestrial fiber networks. Data multiplexing over the satellite is accomplished using time-division multiple access (TDMA) techniques coordinated with the switching and beam hopping facilities provided by ACTS. Transmissions through the satellite are protected with Reed-Solomon encoding. providing virtually error-free transmission under most weather conditions. Unique to the system are a TDMA frame structure and satellite synchronization mechanism that allow: (a) very efficient utilization of the satellite capacity: (b) over-the-satellite dosed-loop synchronization of the network in configurations with up to 64 ground stations: and (c) ground station initial acquisition without collisions with existing signalling or data traffic. The user interfaces are compatible with SONET standards, performing the function of conventional SONET multiplexers and. as such. can be: readily integrated with standard SONET fiber-based terrestrial networks. Management of the network is based upon the simple network management protocol (SNMP). and includes an over-the-satellite signalling network and backup terrestrial internet (IP-based) connectivity. A description of the ground stations is also included.

  3. Using Structure-Based Organic Chemistry Online Tutorials with Automated Correction for Student Practice and Review

    Science.gov (United States)

    O'Sullivan, Timothy P.; Hargaden, Gra´inne C.

    2014-01-01

    This article describes the development and implementation of an open-access organic chemistry question bank for online tutorials and assessments at University College Cork and Dublin Institute of Technology. SOCOT (structure-based organic chemistry online tutorials) may be used to supplement traditional small-group tutorials, thereby allowing…

  4. EFFECTIVE ELECTRONIC TUTORIAL

    Directory of Open Access Journals (Sweden)

    Andrei A. Fedoseev

    2014-01-01

    Full Text Available The article analyzes effective electronic tutorials creation and application based on the theory of pedagogy. Herewith the issues of necessary electronic tutorial functional, ways of the educational process organization with the use of information and communication technologies and the logistics of electronic educational resources are touched upon. 

  5. Creating library tutorials for nursing students.

    Science.gov (United States)

    Schroeder, Heidi

    2010-04-01

    This article describes one librarian's experiences with creating, promoting, and assessing online library tutorials. Tutorials were designed to provide on-demand and accessible library instruction to nursing students at Michigan State University. Topics for tutorials were chosen based on the librarian's liaison experiences and suggestions from nursing faculty. The tutorials were created using Camtasia and required the application of several tools and techniques. Tutorials were promoted through Web pages, the ANGEL course management system, blog posts, librarian interactions, e-mails, and more. In order to assess the tutorials' perceived effectiveness, feedback was gathered using a short survey. Future plans for the nursing tutorials project are also discussed.

  6. The effectiveness of web-based, multimedia tutorials for teaching methods of human body composition analysis.

    Science.gov (United States)

    Buzzell, Paul R; Chamberlain, Valerie M; Pintauro, Stephen J

    2002-12-01

    This study examined the effectiveness of a series of Web-based, multimedia tutorials on methods of human body composition analysis. Tutorials were developed around four body composition topics: hydrodensitometry (underwater weighing), dual-energy X-ray absorptiometry, bioelectrical impedance analysis, and total body electrical conductivity. Thirty-two students enrolled in the course were randomly assigned to learn the material through either the Web-based tutorials only ("Computer"), a traditional lecture format ("Lecture"), or lectures supplemented with Web-based tutorials ("Both"). All students were administered a validated pretest before randomization and an identical posttest at the completion of the course. The reliability of the test was 0.84. The mean score changes from pretest to posttest were not significantly different among the groups (65.4 plus minus 17.31, 78.82 plus minus 21.50, and 76 plus minus 21.22 for the Computer, Both, and Lecture groups, respectively). Additionally, a Likert-type assessment found equally positive attitudes toward all three formats. The results indicate that Web-based tutorials are as effective as the traditional lecture format for teaching these topics.

  7. The Web Lecture Archive Project: Archiving ATLAS Presentations and Tutorials

    CERN Multimedia

    Herr, J

    2004-01-01

    The geographical diversity of the ATLAS Collaboration presents constant challenges in the communication between and training of its members. One important example is the need for training of new collaboration members and/or current members on new developments. The Web Lecture Archive Project (WLAP), a joint project between the University of Michigan and CERN Technical Training, has addressed this challenge by recording ATLAS tutorials in the form of streamed "Web Lectures," consisting of synchronized audio, video and high-resolution slides, available on demand to anyone in the world with a Web browser. ATLAS software tutorials recorded by WLAP include ATHENA, ATLANTIS, Monte Carlo event generators, Object Oriented Analysis and Design, GEANT4, and Physics EDM and tools. All ATLAS talks, including both tutorials and meetings are available at http://www.wlap.org/browser.php?ID=atlas. Members of the University of Michigan Physics Department and Media Union, under the framework of the ATLAS Collaboratory Project ...

  8. The Implementation of Blended Learning Using Android-Based Tutorial Video in Computer Programming Course II

    Science.gov (United States)

    Huda, C.; Hudha, M. N.; Ain, N.; Nandiyanto, A. B. D.; Abdullah, A. G.; Widiaty, I.

    2018-01-01

    Computer programming course is theoretical. Sufficient practice is necessary to facilitate conceptual understanding and encouraging creativity in designing computer programs/animation. The development of tutorial video in an Android-based blended learning is needed for students’ guide. Using Android-based instructional material, students can independently learn anywhere and anytime. The tutorial video can facilitate students’ understanding about concepts, materials, and procedures of programming/animation making in detail. This study employed a Research and Development method adapting Thiagarajan’s 4D model. The developed Android-based instructional material and tutorial video were validated by experts in instructional media and experts in physics education. The expert validation results showed that the Android-based material was comprehensive and very feasible. The tutorial video was deemed feasible as it received average score of 92.9%. It was also revealed that students’ conceptual understanding, skills, and creativity in designing computer program/animation improved significantly.

  9. Directional Networking in GPS Denied Environments - Time Synchronization

    Science.gov (United States)

    2016-03-14

    RF-based measurements to synchronize time and measure node range.  Satellite Doppler: Using Doppler measurements from multiple satellites along...with satellite catalog data to determine time and position.  LTE : Use existing LTE base-stations for time and position.  Differential GPS: A...Opportunistic Signals: Opportunistically take advantage of existing RF signals (i.e., FM radio, DTV, LTE , etc.) transmitted from known locations

  10. The Orbital Dynamics of Synchronous Satellites: Irregular Motions in the 2 : 1 Resonance

    Directory of Open Access Journals (Sweden)

    Jarbas Cordeiro Sampaio

    2012-01-01

    Full Text Available The orbital dynamics of synchronous satellites is studied. The 2 : 1 resonance is considered; in other words, the satellite completes two revolutions while the Earth completes one. In the development of the geopotential, the zonal harmonics J20 and J40 and the tesseral harmonics J22 and J42 are considered. The order of the dynamical system is reduced through successive Mathieu transformations, and the final system is solved by numerical integration. The Lyapunov exponents are used as tool to analyze the chaotic orbits.

  11. A precise time synchronization method for 5G based on radio-over-fiber network with SDN controller

    Science.gov (United States)

    He, Linkuan; Wei, Baoguo; Yang, Hui; Yu, Ao; Wang, Zhengyong; Zhang, Jie

    2018-02-01

    There is an increasing demand on accurate time synchronization with the growing bandwidth of network service for 5G. In 5G network, it's necessary for base station to achieve accurate time synchronization to guarantee the quality of communication. In order to keep accuracy time for 5G network, we propose a time synchronization system for satellite ground station based on radio-over-fiber network (RoFN) with software defined optical network (SDON) controller. The advantage of this method is to improve the accuracy of time synchronization of ground station. The IEEE 1588 time synchronization protocol can solve the problems of high cost and lack of precision. However, in the process of time synchronization, distortion exists during the transmission of digital time signal. RoF uses analog optical transmission links and therefore analog transmission can be implemented among ground stations instead of digital transmission, which means distortion and bandwidth waste in the process of digital synchronization can be avoided. Additionally, the thought of SDN, software defined network, can optimize RoFN with centralized control and simplifying base station. Related simulation had been carried out to prove its superiority.

  12. The rediscovery of synchronous reluctance and ferrite permanent magnet motors tutorial course notes

    CERN Document Server

    Pellegrino, Gianmario; Bianchi, Nicola; Soong, Wen; Cupertino, Francesco

    2016-01-01

    This book offers an essential compendium on the analysis and design of synchronous motors for variable-speed applications. Focusing on synchronous reluctance and ferrite permanent-magnet (PM) synchronous reluctance machines, it provides a broad perspective on three-phase machines for variable speed applications, a field currently dominated by asynchronous machines and rare-earth PM synchronous machines. It also describes synchronous reluctance machines and PM machines without rare-earth materials, comparing them to state-of-the-art solutions. The book provides readers with extensive information on and finite element models of PM synchronous machines, including all relevant equations and with an emphasis on synchronous-reluctance and PM-assisted synchronous-reluctance machines. It covers ferrite-assisted machines, modeled as a subcase of PM-assistance, fractional slot combinations solutions, and a quantitative, normalized comparison of torque capability with benchmark PM machines. The book discusses a wealth o...

  13. Research and Realization of the HJ-1C Real-time Software Frame Synchronization Algorithm

    Directory of Open Access Journals (Sweden)

    Hou Yang-shuan

    2014-06-01

    Full Text Available Conventional software frame synchronization methods are inefficient in processing huge continuous data without synchronization words. To improve the processing speed, a real-time synchronization algorithm is proposed based on reverse searching. Satellite data are grouped and searched in the reverse direction to avoid searching for synchronization words in huge continuous invalid data; thus, the frame synchronization speed is improved enormously. The fastest processing speed is up to 15445.9 Mbps when HJ-1C data are tested. This method is presently applied to the HJ-1C quick-look system in remote sensing satellite ground stations.

  14. [The opinion of teachers about tutorial problem based learning].

    Science.gov (United States)

    Navarro H, Nancy; Zamora S, José

    2014-08-01

    In 2004 the Faculty of Medicine of Universidad de La Frontera in Chile implemented curricular changes, incorporating small group problem based learning in different carriers. To explore aspects that hamper or facilitate tutorial problem based learning from the perspective of tutors. Six in depth interviews and a focus group with tutors were carried out in 2010 and 2011. Data were analyzed through constant comparisons using the program ATLAS ti, guaranteeing credibility, reliance, validation and transferability. Five hundred and twenty eight (528) significance units were identified and 25 descriptive categories emerged. The categories of tutor motivation, methodological domain, tutor responsibility, tutor critical capacity, disciplinary domain, student participation and tutor-student interaction were emphasized. Three qualitative domains were generated, namely tutor skills, transformation of student roles and institutional commitment. Tutorial teaching is favored by teachers when the institutions train them in the subject, when there is administrative support and an adequate infrastructure and coordination.

  15. Research on orbit prediction for solar-based calibration proper satellite

    Science.gov (United States)

    Chen, Xuan; Qi, Wenwen; Xu, Peng

    2018-03-01

    Utilizing the mathematical model of the orbit mechanics, the orbit prediction is to forecast the space target's orbit information of a certain time based on the orbit of the initial moment. The proper satellite radiometric calibration and calibration orbit prediction process are introduced briefly. On the basis of the research of the calibration space position design method and the radiative transfer model, an orbit prediction method for proper satellite radiometric calibration is proposed to select the appropriate calibration arc for the remote sensor and to predict the orbit information of the proper satellite and the remote sensor. By analyzing the orbit constraint of the proper satellite calibration, the GF-1solar synchronous orbit is chose as the proper satellite orbit in order to simulate the calibration visible durance for different satellites to be calibrated. The results of simulation and analysis provide the basis for the improvement of the radiometric calibration accuracy of the satellite remote sensor, which lays the foundation for the high precision and high frequency radiometric calibration.

  16. Effects of implementation of problem-based learning tutorials on fifth-year pharmacy students and future issues.

    Science.gov (United States)

    Sato, Atsuko; Morone, Mieko; Azuma, Yutaka

    2011-01-01

    At Tohoku Pharmaceutical University, problem-based learning (PBL) tutorials were incorporated into "prescription analysis" and "case analysis" for fifth-year students in 2010 with the following objectives: ① application and confirmation of acquired knowledge and skills, and acquisition of ② communication ability, ③ presentation ability, ④ cooperativeness through groupwork, and ⑤ information collecting ability. In the present study, we conducted a questionnaire survey on a total of 158 fifth-year students in order to investigate the educational benefits of PBL tutorials. The results showed that the above five objectives of PBL tutorials were being achieved, and confirmed the educational benefits expected of PBL tutorials. In contrast, it was found to be necessary to improve the contents of scenarios and lectures, time allocation regarding schedules, the learning environment, the role of tutors, and other matters. In order to maximize the educational benefits of PBL tutorials, it will be necessary in the future to continue to conduct surveys on students and make improvements to the curriculum based on survey results.

  17. Proposing a Web-Based Tutorial System to Teach Malay Language Braille Code to the Sighted

    Science.gov (United States)

    Wah, Lee Lay; Keong, Foo Kok

    2010-01-01

    The "e-KodBrailleBM Tutorial System" is a web-based tutorial system which is specially designed to teach, facilitate and support the learning of Malay Language Braille Code to individuals who are sighted. The targeted group includes special education teachers, pre-service teachers, and parents. Learning Braille code involves memorisation…

  18. Optimization method of star tracker orientation for sun-synchronous orbit based on space light distribution.

    Science.gov (United States)

    Wang, Geng; Xing, Fei; Wei, Minsong; Sun, Ting; You, Zheng

    2017-05-20

    Star trackers, optical attitude sensors with high precision, are susceptible to space light from the Sun and the Earth albedo. Until now, research in this field has lacked systematic analysis. In this paper, we propose an installation orientation method for a star tracker onboard sun-synchronous-orbit spacecraft and analyze the space light distribution by transforming the complicated relative motion among the Sun, Earth, and the satellite to the body coordinate system of the satellite. Meanwhile, the boundary-curve equations of the areas exposed to the stray light from the Sun and the Earth albedo were calculated by the coordinate-transformation matrix under different maneuver attitudes, and the installation orientation of the star tracker was optimized based on the boundary equations instead of the traditional iterative simulation method. The simulation and verification experiment indicate that this installation orientation method is effective and precise and can provide a reference for the installation of sun-synchronous orbit star trackers free from the stray light.

  19. Video-Tutorial de la base de datos “Grape Genome Browser”

    OpenAIRE

    Cross, Ismael; Rebordinos, Laureana

    2012-01-01

    En este video-tutorial se puede aprender a manejar la base de datos de internet donde está depositada la secuencia del genoma de la vid y acceder e interpretar los resultados de las búsquedas así como la integración con otras bases de datos.

  20. Online Hotseat Tutorials

    DEFF Research Database (Denmark)

    Bengtsen, Søren Smedegaard; Nørgård, Rikke Toft; Dalsgaard, Christian

    . On the grounds of the developed pedagogical format, students elicit advanced academic competences such as being facilitators of critical dialogue, exhibiting knowledge stewardship, and taking on responsibility of relationship formation between students. These are traits we normally see only teachers......We present a design-based research experiment for developing a pedagogical format for supervision collectives called ’online hotseat tutorials.’ The format has been developed and tested within the MA Programme ICT-based educational design, Aarhus University 2014-2018. It has affinity to traditional......-up as well as the pedagogical intentions behind it is presented. Finally, we analyse the emerging forms of partnership within online hot seat tutorials, and we discuss the pedagogical implications for how to further inform, qualify and develop pedagogical formats for team-based supervision in higher...

  1. Research and Realization of the HJ-1C Real-time Software Frame Synchronization Algorithm

    OpenAIRE

    Hou Yang-shuan; Shi Tao; Hu Yu-xin

    2014-01-01

    Conventional software frame synchronization methods are inefficient in processing huge continuous data without synchronization words. To improve the processing speed, a real-time synchronization algorithm is proposed based on reverse searching. Satellite data are grouped and searched in the reverse direction to avoid searching for synchronization words in huge continuous invalid data; thus, the frame synchronization speed is improved enormously. The fastest processing speed is up to 15445.9 M...

  2. The BTeV Software Tutorial Suite

    International Nuclear Information System (INIS)

    Kutschke, Robert K.

    2004-01-01

    The BTeV Collaboration is starting to develop its C++ based offline software suite, an integral part of which is a series of tutorials. These tutorials are targeted at a diverse audience, including new graduate students, experienced physicists with little or no C++ experience, those with just enough C++ to be dangerous, and experts who need only an overview of the available tools. The tutorials must both teach C++ in general and the BTeV specific tools in particular. Finally, they must teach physicists how to find and use the detailed documentation. This report will review the status of the BTeV experiment, give an overview of the plans for and the state of the software and will then describe the plans for the tutorial suite

  3. The acquisition and retention of ECG interpretation skills after a standardized web-based ECG tutorial

    DEFF Research Database (Denmark)

    Rolskov Bojsen, Signe; Räder, Sune Bernd Emil Werner; Holst, Anders Gaardsdal

    2015-01-01

    BACKGROUND: Electrocardiogram (ECG) interpretation is of great importance for patient management. However, medical students frequently lack proficiency in ECG interpretation and rate their ECG training as inadequate. Our aim was to examine the effect of a standalone web-based ECG tutorial...... and to assess the retention of skills using multiple follow-up intervals. METHODS: 203 medical students were included in the study. All participants completed a pre-test, an ECG tutorial, and a post-test. The participants were also randomised to complete a retention-test after short (2-4 weeks), medium (10.......6), respectively). When comparing the pre-test to retention-test delta scores, junior students had learned significantly more than senior students (junior students improved 10.7 points and senior students improved 4.7 points, p = 0.003). CONCLUSION: A standalone web-based ECG tutorial can be an effective means...

  4. Biology and Nursing Students’ Perceptions of a Web-based Information Literacy Tutorial

    Directory of Open Access Journals (Sweden)

    Sharon Weiner

    2012-04-01

    Full Text Available This study assessed student perceptions about an online information literacy tutorial, CORE (Comprehensive Online Research Education, to plan for the next generation of tutorials. The CORE tutorial includes seven modules: “Planning Your Project,” “Topic Exploration,” “Types of Information,” “Search Tools,” “Search Strategies,” “Evaluating Sources,” and “Copyright, Plagiarism, and Citing Sources.” First-year students in biology and nursing courses responded to a survey after they completed the CORE modules. The students liked learning through an online tutorial. They thought that the tutorial could be improved with shorter modules and the addition of video and audio content. Few students reported learning important information from the “Copyright, Plagiarism, and Citing Sources,” “Evaluating Resources,” and “Types of Information” modules. They suggested topics for additional tutorials: how to use library databases and Microsoft Excel; how to evaluate the quality of information, how to cite references in a bibliography, and how to find statistics.

  5. Teaching Game Programming using Video Tutorials

    DEFF Research Database (Denmark)

    Majgaard, Gunver

    . & Squire K. (2004). Design-Based Research: Putting a Stake in the Ground. Journal of Learning Sciences Vol. 13-1. Lave, J., & Wenger, E. (1991). Situated Learning: Legitimate Peripheral Participation, Cambridge: Cambridge Univ. Majgaard, G. (2014). Teaching Design of Emerging Embodied Technologies......Background. What are the learning potentials of using online video tutorials as educational tools in game programming of Mixed Reality? The paper reports on the first experiences of teaching third semester engineering students design of Mixed Reality using online step-by-step programming video...... production makes video tutorials a promising alternative to paper tutorials. Software and game engine companies such as Unity has already switched to video and other online materials as the primary medium for their tutorials. It is often hard to find up to date thoroughly worked through textbooks on new...

  6. Chaos synchronization based on contraction principle

    International Nuclear Information System (INIS)

    Wang Junwei; Zhou Tianshou

    2007-01-01

    This paper introduces contraction principle. Based on such a principle, a novel scheme is proposed to synchronize coupled systems with global diffusive coupling. A rigorous sufficient condition on chaos synchronization is derived. As an example, coupled Lorenz systems with nearest-neighbor diffusive coupling are investigated, and numerical simulations are given to validate the proposed synchronization approach

  7. Historical Text Comprehension Reflective Tutorial Dialogue System

    Science.gov (United States)

    Grigoriadou, Maria; Tsaganou, Grammatiki; Cavoura, Theodora

    2005-01-01

    The Reflective Tutorial Dialogue System (ReTuDiS) is a system for learner modelling historical text comprehension through reflective dialogue. The system infers learners' cognitive profiles and constructs their learner models. Based on the learner model the system plans the appropriate--personalized for learners--reflective tutorial dialogue in…

  8. Stroboscope Based Synchronization of Full Frame CCD Sensors

    OpenAIRE

    Shen, Liang; Feng, Xiaobing; Zhang, Yuan; Shi, Min; Zhu, Dengming; Wang, Zhaoqi

    2017-01-01

    The key obstacle to the use of consumer cameras in computer vision and computer graphics applications is the lack of synchronization hardware. We present a stroboscope based synchronization approach for the charge-coupled device (CCD) consumer cameras. The synchronization is realized by first aligning the frames from different video sequences based on the smear dots of the stroboscope, and then matching the sequences using a hidden Markov model. Compared with current synchronized capture equi...

  9. XTCE: XML Telemetry and Command Exchange Tutorial, XTCE Version 1

    Science.gov (United States)

    Rice, Kevin; Kizzort, Brad

    2008-01-01

    These presentation slides are a tutorial on XML Telemetry and Command Exchange (XTCE). The goal of XTCE is to provide an industry standard mechanism for describing telemetry and command streams (particularly from satellites.) it wiill lower cost and increase validation over traditional formats, and support exchange or native format.XCTE is designed to describe bit streams, that are typical of telemetry and command in the historic space domain.

  10. Stroboscope Based Synchronization of Full Frame CCD Sensors.

    Science.gov (United States)

    Shen, Liang; Feng, Xiaobing; Zhang, Yuan; Shi, Min; Zhu, Dengming; Wang, Zhaoqi

    2017-04-07

    The key obstacle to the use of consumer cameras in computer vision and computer graphics applications is the lack of synchronization hardware. We present a stroboscope based synchronization approach for the charge-coupled device (CCD) consumer cameras. The synchronization is realized by first aligning the frames from different video sequences based on the smear dots of the stroboscope, and then matching the sequences using a hidden Markov model. Compared with current synchronized capture equipment, the proposed approach greatly reduces the cost by using inexpensive CCD cameras and one stroboscope. The results show that our method could reach a high accuracy much better than the frame-level synchronization of traditional software methods.

  11. Recent developments in computer vision-based analytical chemistry: A tutorial review.

    Science.gov (United States)

    Capitán-Vallvey, Luis Fermín; López-Ruiz, Nuria; Martínez-Olmos, Antonio; Erenas, Miguel M; Palma, Alberto J

    2015-10-29

    Chemical analysis based on colour changes recorded with imaging devices is gaining increasing interest. This is due to its several significant advantages, such as simplicity of use, and the fact that it is easily combinable with portable and widely distributed imaging devices, resulting in friendly analytical procedures in many areas that demand out-of-lab applications for in situ and real-time monitoring. This tutorial review covers computer vision-based analytical (CVAC) procedures and systems from 2005 to 2015, a period of time when 87.5% of the papers on this topic were published. The background regarding colour spaces and recent analytical system architectures of interest in analytical chemistry is presented in the form of a tutorial. Moreover, issues regarding images, such as the influence of illuminants, and the most relevant techniques for processing and analysing digital images are addressed. Some of the most relevant applications are then detailed, highlighting their main characteristics. Finally, our opinion about future perspectives is discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Selection of the signal synchronization method in software GPS receivers

    Directory of Open Access Journals (Sweden)

    Vlada S. Sokolović

    2011-04-01

    Full Text Available Introduction This paper presents a critical analysis of the signal processing flow carried out in a software GPS receiver and a critical comparison of different architectures for signal processing within the GPS receiver. A model of software receivers is shown. Based on the displayed model, a receiver has been realized in the MATLAB software package, in which the simulations of signal processing were carried out. The aim of this paper is to demonstrate the advantages and disadvantages of different methods of the synchronization of signals in the receiver, and to propose a solution acceptable for possible implementation. The signal processing flow was observed from the input circuit to the extraction of the bits of the navigation message. The entire signal processing was performed on the L1 signal and the data collected by the input circuit SE4110. A radio signal from the satellite was accepted with the input circuit, filtered and translated into a digital form. The input circuit ends with the hardware of the receiver. A digital signal from the input circuit is brought into the PC Pentium 4 (AMD 3000 + where the receiver is realized in Matlab. Model of software GPS receiver The first level of processing is signal acquisition. Signal acquisition was realized using the cyclic convolution. The acquisition process was carried out by measuring signals from satellites, and these parameters are passed to the next level of processing. The next level was done by monitoring the synchronization signal and extracting the navigation message bits. On the basis of the detection of the navigation message the receiver calculates the position of a satellite and then, based on the position of the satellite, its own position. Tracking of GPS signal synchronization In order to select the most acceptable method of signal synchronization in the receiver, different methods of signal synchronization are compared. The early-late-DLL (Delay Lock Loop, TDL (Tau Dither Loop

  13. A test of the design of a video tutorial for software training

    NARCIS (Netherlands)

    van der Meij, Jan; van der Meij, Hans

    2015-01-01

    The effectiveness of a video tutorial versus a paper-based tutorial for software training has yet to be established. Mixed outcomes from the empirical studies to date suggest that for a video tutorial to outperform its paper-based counterpart, the former should be crafted so that it addresses the

  14. Video and HTML: Testing Online Tutorial Formats with Biology Students

    Science.gov (United States)

    Craig, Cindy L.; Friehs, Curt G.

    2013-01-01

    This study compared two common types of online information literacy tutorials: a streaming media tutorial using animation and narration and a text-based tutorial with static images. Nine sections of an undergraduate biology lab class (234 students total) were instructed by a librarian on how to use the BIOSIS Previews database. Three sections…

  15. Generating Consistent Program Tutorials

    DEFF Research Database (Denmark)

    Vestdam, Thomas

    2002-01-01

    In this paper we present a tool that supports construction of program tutorials. A program tutorial provides the reader with an understanding of an example program by interleaving fragments of source code and explaining text. An example program can for example illustrate how to use a library or a......, and we see potential in using the tool to produce program tutorials to be used for frameworks, libraries, and in educational contexts.......In this paper we present a tool that supports construction of program tutorials. A program tutorial provides the reader with an understanding of an example program by interleaving fragments of source code and explaining text. An example program can for example illustrate how to use a library...... or a framework. We present a means for specifying the fragments of a program that are to be in-lined in the tutorial text. These in-line fragments are defined by addressing named syntactical elements, such as classes and methods, but it is also possible to address individual code lines by labeling them...

  16. Research in Application of Geodetic GPS Receivers in Time Synchronization

    Science.gov (United States)

    Zhang, Q.; Zhang, P.; Sun, Z.; Wang, F.; Wang, X.

    2018-04-01

    In recent years, with the development of satellite orbit and clock parameters accurately determining technology and the popularity of geodetic GPS receivers, Common-View (CV) which proposed in 1980 by Allan has gained widespread application and achieved higher accuracy time synchronization results. GPS Common View (GPS CV) is the technology that based on multi-channel geodetic GPS receivers located in different place and under the same common-view schedule to receiving same GPS satellite signal at the same time, and then calculating the time difference between respective local receiver time and GPST by weighted theory, we will obtain the difference between above local time of receivers that installed in different station with external atomic clock. Multi-channel geodetic GPS receivers have significant advantages such as higher stability, higher accuracy and more common-view satellites in long baseline time synchronization application over the single-channel geodetic GPS receivers. At present, receiver hardware delay and surrounding environment influence are main error factors that affect the accuracy of GPS common-view result. But most error factors will be suppressed by observation data smoothing and using of observation data from different satellites in multi-channel geodetic GPS receiver. After the SA (Selective Availability) cancellation, using a combination of precise satellite ephemeris, ionospheric-free dual-frequency P-code observations and accurately measuring of receiver hardware delay, we can achieve time synchronization result on the order of nanoseconds (ns). In this paper, 6 days observation data of two IGS core stations with external atomic clock (PTB, USNO distance of two stations about 6000 km) were used to verify the GPS common-view theory. Through GPS observation data analysis, there are at least 2-4 common-view satellites and 5 satellites in a few tracking periods between two stations when the elevation angle is 15°, even there will be at least

  17. RESEARCH IN APPLICATION OF GEODETIC GPS RECEIVERS IN TIME SYNCHRONIZATION

    Directory of Open Access Journals (Sweden)

    Q. Zhang

    2018-04-01

    Full Text Available In recent years, with the development of satellite orbit and clock parameters accurately determining technology and the popularity of geodetic GPS receivers, Common-View (CV which proposed in 1980 by Allan has gained widespread application and achieved higher accuracy time synchronization results. GPS Common View (GPS CV is the technology that based on multi-channel geodetic GPS receivers located in different place and under the same common-view schedule to receiving same GPS satellite signal at the same time, and then calculating the time difference between respective local receiver time and GPST by weighted theory, we will obtain the difference between above local time of receivers that installed in different station with external atomic clock. Multi-channel geodetic GPS receivers have significant advantages such as higher stability, higher accuracy and more common-view satellites in long baseline time synchronization application over the single-channel geodetic GPS receivers. At present, receiver hardware delay and surrounding environment influence are main error factors that affect the accuracy of GPS common-view result. But most error factors will be suppressed by observation data smoothing and using of observation data from different satellites in multi-channel geodetic GPS receiver. After the SA (Selective Availability cancellation, using a combination of precise satellite ephemeris, ionospheric-free dual-frequency P-code observations and accurately measuring of receiver hardware delay, we can achieve time synchronization result on the order of nanoseconds (ns. In this paper, 6 days observation data of two IGS core stations with external atomic clock (PTB, USNO distance of two stations about 6000 km were used to verify the GPS common-view theory. Through GPS observation data analysis, there are at least 2–4 common-view satellites and 5 satellites in a few tracking periods between two stations when the elevation angle is 15°, even

  18. Nonlinear observer based phase synchronization of chaotic systems

    International Nuclear Information System (INIS)

    Meng Juan; Wang Xingyuan

    2007-01-01

    This Letter analyzes the phase synchronization problem of autonomous chaotic systems. Based on the nonlinear state observer algorithm and the pole placement technique, a phase synchronization scheme is designed. The phase synchronization of a new chaotic system is achieved by using this observer controller. Numerical simulations further demonstrate the effectiveness of the proposed phase synchronization scheme

  19. Stroboscope Based Synchronization of Full Frame CCD Sensors

    Directory of Open Access Journals (Sweden)

    Liang Shen

    2017-04-01

    Full Text Available The key obstacle to the use of consumer cameras in computer vision and computer graphics applications is the lack of synchronization hardware. We present a stroboscope based synchronization approach for the charge-coupled device (CCD consumer cameras. The synchronization is realized by first aligning the frames from different video sequences based on the smear dots of the stroboscope, and then matching the sequences using a hidden Markov model. Compared with current synchronized capture equipment, the proposed approach greatly reduces the cost by using inexpensive CCD cameras and one stroboscope. The results show that our method could reach a high accuracy much better than the frame-level synchronization of traditional software methods.

  20. A Web-Based Interactive Homework Quiz and Tutorial Package To Motivate Undergraduate Chemistry Students and Improve Learning

    Science.gov (United States)

    Freasier, Ben; Collins, Grant; Newitt, Paula

    2003-11-01

    This study presents a Web-based interactive homework quiz and tutorial package that we have devised to improve the learning of first-year undergraduate chemistry students. We developed this automated scheme, based on WWWAssign, to produce randomly generated quizzes from a large database of questions, instantaneously grade that homework, give a fully-worked solution, and provide individually targeted tutorial assistance. Success in these quizzes was a necessary requirement before taking supervised tests. We found a positive correlation at the p= 0.1 level (90%) between voluntary extra use of the quizzes in the interactive package and the final course grade. All students undertook more quizzes than the base course requirement even though the quiz grades did not contribute to the total course grades. We suggest that students were motivated to pursue additional practice with the quizzes and associated tutorial information, as they perceived some benefit in this student-centered study tool and could access it at any time.

  1. Efficacy of Multimedia Learning Modules as Preparation for Lecture-Based Tutorials in Electromagnetism

    Directory of Open Access Journals (Sweden)

    James Christopher Moore

    2018-02-01

    Full Text Available We have investigated the efficacy of on-line, multimedia learning modules (MLMs as preparation for in-class, lecture-based tutorials in electromagnetism in a physics course for natural science majors (biology and marine science. Specifically, we report the results of a multiple-group pre/post-test research design comparing two groups receiving different treatments with respect to activities preceding participation in Tutorials in Introductory Physics. The different pre-tutorial activities were as follows: (1 students were assigned reading from a traditional textbook, followed by a traditional lecture; and (2 students completed on-line MLMs developed by the Physics Education Research Group at the University of Illinois at Urbana Champaign (UIUC, and commercially known as FlipItPhysics. The MLM treatment group earned significantly higher mid-term examination scores and larger gains in content knowledge as measured by the Conceptual Survey of Electricity and Magnetism (CSEM. Student attitudes towards “reformed” instruction in the form of active-engagement tutorials were also improved. Specifically, post-course surveys showed that MLM-group students believed class time was more effective and the instructor was more clear than reported by non-MLM students, even though there was no significant difference between groups with respect to in-class activities and the same instructor taught both groups. MLM activities can be a highly effective tool for some student populations, especially when student preparation and buy-in are important for realizing significant gains.

  2. Tutorial Facilitation in the Humanities Based on the Tenets of Carl Rogers

    Science.gov (United States)

    Heim, Caroline

    2012-01-01

    This article introduces a model for group facilitation in the humanities based on Carl Rogers' model for group psychotherapy. Certain aspects of Carl Rogers' reflective learning strategies are reappraised and principles, specific only to psychotherapy, are introduced. Five of Rogers' axioms are applied to the tutorial discussion model: a…

  3. Hazardous Solvent Substitution Data System tutorial

    International Nuclear Information System (INIS)

    Twitchell, K.E.; Skinner, N.L.

    1993-07-01

    This manual is the tutorial for the Hazardous Solvent Substitution Data System (HSSDS), an online, comprehensive system of information on alternatives to hazardous solvents and related subjects. The HSSDS data base contains product information, material safety data sheets, toxicity reports, usage reports, biodegradable data, product chemical element lists, and background information on solvents. HSSDS use TOPIC reg-sign to search for information based on a query defined by the user. TOPIC provides a full text retrieval of unstructured source documents. In this tutorial, a series of lessons is provided that guides the user through basic steps common to most queries performed with HSSDS. Instructions are provided for both window-based and character-based applications

  4. Symbol Synchronization for Diffusion-Based Molecular Communications.

    Science.gov (United States)

    Jamali, Vahid; Ahmadzadeh, Arman; Schober, Robert

    2017-12-01

    Symbol synchronization refers to the estimation of the start of a symbol interval and is needed for reliable detection. In this paper, we develop several symbol synchronization schemes for molecular communication (MC) systems where we consider some practical challenges, which have not been addressed in the literature yet. In particular, we take into account that in MC systems, the transmitter may not be equipped with an internal clock and may not be able to emit molecules with a fixed release frequency. Such restrictions hold for practical nanotransmitters, e.g., modified cells, where the lengths of the symbol intervals may vary due to the inherent randomness in the availability of food and energy for molecule generation, the process for molecule production, and the release process. To address this issue, we develop two synchronization-detection frameworks which both employ two types of molecule. In the first framework, one type of molecule is used for symbol synchronization and the other one is used for data detection, whereas in the second framework, both types of molecule are used for joint symbol synchronization and data detection. For both frameworks, we first derive the optimal maximum likelihood (ML) symbol synchronization schemes as performance upper bounds. Since ML synchronization entails high complexity, for each framework, we also propose three low-complexity suboptimal schemes, namely a linear filter-based scheme, a peak observation-based scheme, and a threshold-trigger scheme, which are suitable for MC systems with limited computational capabilities. Furthermore, we study the relative complexity and the constraints associated with the proposed schemes and the impact of the insertion and deletion errors that arise due to imperfect synchronization. Our simulation results reveal the effectiveness of the proposed synchronization schemes and suggest that the end-to-end performance of MC systems significantly depends on the accuracy of the symbol

  5. Solar Tutorial and Annotation Resource (STAR)

    Science.gov (United States)

    Showalter, C.; Rex, R.; Hurlburt, N. E.; Zita, E. J.

    2009-12-01

    We have written a software suite designed to facilitate solar data analysis by scientists, students, and the public, anticipating enormous datasets from future instruments. Our “STAR" suite includes an interactive learning section explaining 15 classes of solar events. Users learn software tools that exploit humans’ superior ability (over computers) to identify many events. Annotation tools include time slice generation to quantify loop oscillations, the interpolation of event shapes using natural cubic splines (for loops, sigmoids, and filaments) and closed cubic splines (for coronal holes). Learning these tools in an environment where examples are provided prepares new users to comfortably utilize annotation software with new data. Upon completion of our tutorial, users are presented with media of various solar events and asked to identify and annotate the images, to test their mastery of the system. Goals of the project include public input into the data analysis of very large datasets from future solar satellites, and increased public interest and knowledge about the Sun. In 2010, the Solar Dynamics Observatory (SDO) will be launched into orbit. SDO’s advancements in solar telescope technology will generate a terabyte per day of high-quality data, requiring innovation in data management. While major projects develop automated feature recognition software, so that computers can complete much of the initial event tagging and analysis, still, that software cannot annotate features such as sigmoids, coronal magnetic loops, coronal dimming, etc., due to large amounts of data concentrated in relatively small areas. Previously, solar physicists manually annotated these features, but with the imminent influx of data it is unrealistic to expect specialized researchers to examine every image that computers cannot fully process. A new approach is needed to efficiently process these data. Providing analysis tools and data access to students and the public have proven

  6. Satellite Communications

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Satellite Communications. Arthur C Clarke wrote a seminal paper in 1945 in wireless world. Use three satellites in geo-synchronous orbit to enable intercontinental communications. System could be realised in '50 to 100 years'

  7. Adding problem-based learning tutorials to a traditional lecture-based curriculum: a pilot study in a dental school.

    Science.gov (United States)

    Katsuragi, Hiroaki

    2005-09-01

    This article reports on the implementation of a problem-based learning (PBL) tutorial in our advanced program for second year students within an existing curriculum. The program was opened on the last 5 days of the summer vacation and students could volunteer to be part of the group. Students separated themselves into small groups by random sampling. The PBL tutorials were done during the first 3 days for medical problems according to our original scenarios (based on medical cases), and during the last 2 days, students made presentations of their learning outcomes, using information technology (IT) by themselves. Throughout this program, students were expected to engage in self-learning, except for a 1(1/2)-h group session with a tutor. Assessment was done by attendance at a group session and by portfolio analysis. Following the portfolio analysis, students identified the number of learning issues (group A, 26 +/- 7 issues; group B, 20 +/- 3 issues; group C, 21 +/- 7 issues). Research, by questionnaire, revealed that 84% of the students were strongly interested in each scenario and 95% of the students felt familiar with each scenario. The levels of satisfaction with the tutor were different in the three groups. All of the students were comfortable in the discussion room and IT center. These results suggested that PBL tutorials are supported by the scenario, the tutor, and the location of the group session, as well as by self-learning. Moreover, one of the most important factors for a PBL tutorial that the student is ready for the free discussions and has enough time for individual self-learning.

  8. Difficult incidents and tutor interventions in problem-based learning tutorials.

    Science.gov (United States)

    Kindler, Pawel; Grant, Christopher; Kulla, Steven; Poole, Gary; Godolphin, William

    2009-09-01

    Tutors report difficult incidents and distressing conflicts that adversely affect learning in their problem-based learning (PBL) groups. Faculty development (training) and peer support should help them to manage this. Yet our understanding of these problems and how to deal with them often seems inadequate to help tutors. The aim of this study was to categorise difficult incidents and the interventions that skilled tutors used in response, and to determine the effectiveness of those responses. Thirty experienced and highly rated tutors in our Year 1 and 2 medical curriculum took part in semi-structured interviews to: identify and describe difficult incidents; describe how they responded, and assess the success of each response. Recorded and transcribed data were analysed thematically to develop typologies of difficult incidents and interventions and compare reported success or failure. The 94 reported difficult incidents belonged to the broad categories 'individual student' or 'group dynamics'. Tutors described 142 interventions in response to these difficult incidents, categorised as: (i) tutor intervenes during tutorial; (ii) tutor gives feedback outside tutorial, or (iii) student or group intervenes. Incidents in the 'individual student' category were addressed relatively unsuccessfully (effective 75% of the time) by response (iii). None of the interventions worked well when used in response to problems related to 'group dynamics'. Overall, 59% of the difficult incidents were dealt with successfully. Dysfunctional PBL groups can be highly challenging, even for experienced and skilled tutors. Within-tutorial feedback, the treatment that tutors are most frequently advised to apply, was often not effective. Our study suggests that the collective responsibility of the group, rather than of the tutor, to deal with these difficulties should be emphasised.

  9. Dealing with Conflicts on Knowledge in Tutorial Groups

    Science.gov (United States)

    Aarnio, Matti; Lindblom-Ylanne, Sari; Nieminen, Juha; Pyorala, Eeva

    2013-01-01

    The aim of our study was to gain understanding of different types of conflicts on knowledge in the discussions of problem-based learning tutorial groups, and how such conflicts are dealt with. We examined first-year medical and dental students' (N = 33) conflicts on knowledge in four videotaped reporting phase tutorials. A coding scheme was…

  10. IPTV inter-destination synchronization: A network-based approach

    NARCIS (Netherlands)

    Stokking, H.M.; Deventer, M.O. van; Niamut, O.A.; Walraven, F.A.; Mekuria, R.N.

    2010-01-01

    This paper introduces a novel network-based approach to inter-destination media synchronization. The approach meets the need for synchronization in advanced TV concepts like social TV and offers high scalability, unlike conventional end-point based approaches. The solution for interdestination media

  11. A Tutorial Programme to Enhance Psychiatry Learning Processes within a PBL-Based Course

    Science.gov (United States)

    Hood, Sean; Chapman, Elaine

    2011-01-01

    This paper describes a tutorial programme developed at the University of Western Australia (UWA) to enhance medical students' learning processes within problem-based learning contexts. The programme encourages students to use more effective learning approaches by scaffolding the development of effective problem-solving strategies, and by reducing…

  12. A clock synchronization skeleton based on RTAI

    NARCIS (Netherlands)

    Huang, Y.; Visser, P.M.; Broenink, Johannes F.

    2006-01-01

    This paper presents a clock synchronization skeleton based on RTAI (Real Time Application Interface). The skeleton is a thin layer that provides unified but extendible interfaces to the underlying operating system, the synchronization algorithms and the upper level applications in need of clock

  13. Observer-based hyperchaos synchronization in cascaded discrete-time systems

    International Nuclear Information System (INIS)

    Grassi, Giuseppe

    2009-01-01

    This paper deals with the observer-based synchronization in a cascade connection of hyperchaotic discrete-time systems. The paper demonstrates that exact synchronization in finite time is achievable between pairs of drive-response systems using only a scalar synchronizing signal. This 'propagated synchronization' starts from the innermost drive-response system pair and propagates toward the outermost drive-system pair. Choosing the drive-system input to be an information signal (encrypted via an arbitrary encryption function) yields a potential application of this architecture in chaos-based communications.

  14. Development of cyberblog-based intelligent tutorial system to improve students learning ability algorithm

    Science.gov (United States)

    Wahyudin; Riza, L. S.; Putro, B. L.

    2018-05-01

    E-learning as a learning activity conducted online by the students with the usual tools is favoured by students. The use of computer media in learning provides benefits that are not owned by other learning media that is the ability of computers to interact individually with students. But the weakness of many learning media is to assume that all students have a uniform ability, when in reality this is not the case. The concept of Intelligent Tutorial System (ITS) combined with cyberblog application can overcome the weaknesses in neglecting diversity. An Intelligent Tutorial System-based Cyberblog application (ITS) is a web-based interactive application program that implements artificial intelligence which can be used as a learning and evaluation media in the learning process. The use of ITS-based Cyberblog in learning is one of the alternative learning media that is interesting and able to help students in measuring ability in understanding the material. This research will be associated with the improvement of logical thinking ability (logical thinking) of students, especially in algorithm subjects.

  15. Computer Tutorial Programs in Physics.

    Science.gov (United States)

    Faughn, Jerry; Kuhn, Karl

    1979-01-01

    Describes a series of computer tutorial programs which are intended to help college students in introductory physics courses. Information about these programs, which are either calculus or algebra-trig based, is presented. (HM)

  16. Medical student perceptions of factors affecting productivity of problem-based learning tutorial groups: does culture influence the outcome?

    Science.gov (United States)

    Das Carlo, Mandira; Swadi, Harith; Mpofu, Debbie

    2003-01-01

    The popularization of problem-based learning (PBL) has drawn attention to the motivational and cognitive skills necessary for medical students in group learning. This study identifies the effect of motivational and cognitive factors on group productivity of PBL tutorial groups. A self-administered questionnaire was completed by 115 students at the end of PBL tutorials for 4 themes. The questionnaire explored student perceptions about effect of motivation, cohesion, sponging, withdrawal, interaction, and elaboration on group productivity. We further analyzed (a) differences in perceptions between male and female students, (b) effect of "problems," and (c) effect of student progress over time on group productivity. There were linear relations between a tutorial group's success and the factors studied. Significant differences were noted between male and female student groups. Students and tutors need to recognize symptoms of ineffective PBL groups. Our study emphasizes the need to take into account cultural issues in setting ground rules for PBL tutorials.

  17. Implementation of Inquiry-Based Tutorials in AN Introductory Physics Course: the Role of the Graduate Teaching Assistant.

    Science.gov (United States)

    Thoresen, Carol Wiggins

    1994-01-01

    This study determined if the training provided physics teaching assistants was sufficient to accomplish the objectives of inquiry-based tutorials for an introductory physics course. Qualitative research methods were used: (1) to determine if the Physics by Inquiry method was modeled; (2) to describe the process from the teaching assistant perspective; (3) to determine TA opinions on training methods; (4) to develop a frame of reference to better understand the role of TA's as instructional support staff. The study determined that the teaching assistants verbalized appropriate instructional actions, but were observed to use a predominantly didactic teaching style. TA's held a variety of perceptions and beliefs about inquiry -based learning and how science is learned. They felt comfortable in the role of tutorial instructor. They were satisfied with the training methods provided and had few suggestions to change or improve training for future tutorial instructors. A concurrent theme of teacher action dependent on teacher beliefs was sustained throughout the study. The TA's actions, as tutorial instructors, reflected their educational beliefs, student background and learning experiences. TA's performance as tutorial instructors depended on what they think and believe about learning science. Practical implications exist for training teaching assistants to be tutorial instructors. Some recommendations may be appropriate for TA's required to use instructional methods that they have not experienced as students. Interview prospective teaching assistants to determine educational experience and beliefs. Employ inexperienced teaching assistants whose perspectives match the proposed instructional role and who might be more receptive to modeling. Incorporate training into staff meetings. Provide time for TA's to experience the instructional model with simulation or role play as students and as instructors, accompanied by conference discussion. Use strategies known to enhance

  18. Projective synchronization based on suitable separation

    International Nuclear Information System (INIS)

    Li Guohui; Xiong Chuan; Sun Xiaonan

    2007-01-01

    A new approach for constructing a projective-synchronized chaotic slave system is proposed in this paper. This method is based on suitable separation by decomposing the system as the linear part and the nonlinear one. From matrix measure theory, some simple but efficient criteria are derived for projective synchronization of chaotic system. Numerical simulations for the Lorenz system show that this control method works very well

  19. SRA Grant Writing Tutorial

    Science.gov (United States)

    This tutorial will help give your organization a broad but succinct analysis of what the SRA grant program is about. This self-paced tutorial is organized under two segments: Overview of Grant Program and Program Details.

  20. ROOT Tutorial for Summer Students

    CERN Multimedia

    CERN. Geneva; Piparo, Danilo

    2015-01-01

    ROOT is a "batteries-included" tool kit for data analysis, storage and visualization. It is widely used in High Energy Physics and other disciplines such as Biology, Finance and Astrophysics. This event is an introductory tutorial to ROOT and comprises a front lecture and hands on exercises. IMPORTANT NOTE: The tutorial is based on ROOT 6.04 and NOT on the ROOT5 series.  IMPORTANT NOTE: if you have ROOT 6.04 installed on your laptop, you will not need to install any virtual machine. The instructions showing how to install the virtual machine on which you can find ROOT 6.04 can be found under "Material" on this page.

  1. Interactive Intragroup Tutorials: A Need-Based Modification to Enhance Learning in Physiology

    Science.gov (United States)

    Srivastava, Tripti K.; Waghmare, Lalitbhushan S.; Jagzape, Arunita; Mishra, Vedprakash

    2015-01-01

    A tutorial is a period of instruction given by a university or college tutor to an individual or a very small group. Essentially, it is a small class of a few students in which the tutor (a lecturer or other academic staff member) gives individual attention to every learner. The tutorial focuses on certain subject areas and generally proceeds with…

  2. Historical review of tutorial in education

    Directory of Open Access Journals (Sweden)

    María Gabriela Luna Pérez

    2015-01-01

    Full Text Available For centuries, tutorials have always been of an individual character in the history of education. The paper reviews how tutorials in education have evolved from ancient Greece to the present by considering taking into account the following aspects: a its general understanding, b the favorite areas of orientation c the role of learning guiding process d the supporting role of tutorials. We offer a historical account of tutorials development in Mexican Education. The study provides the main trends of tutorial activities in primary education, the evidence confirmed that tutoring has evolved from the learning of philosophical and ethical questions to the multiple learning involving competencies.

  3. Efficacy of Multimedia Learning Modules as Preparation for Lecture-Based Tutorials in Electromagnetism

    Science.gov (United States)

    Moore, James Christopher

    2018-01-01

    We have investigated the efficacy of on-line, multimedia learning modules (MLMs) as preparation for in-class, lecture-based tutorials in electromagnetism in a physics course for natural science majors (biology and marine science). Specifically, we report the results of a multiple-group pre/post-test research design comparing two groups receiving…

  4. A 5' online tutorial about 'how to prepare for a 5' online tutorial'

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    This 4' video summarises our experience from short online tutorial recordings for the last 6 months. It contains important points for speakers' preparation and things to observe during the online tutorial recordings. For more details, check out our e-learning twiki.

  5. First Year Distance Transition Pedagogy: Synchronous online classrooms

    Directory of Open Access Journals (Sweden)

    Wendy Fasso

    2013-04-01

    Full Text Available The design and facilitation of distance online courses for first year students must consider both first year, and distance pedagogy. One technology with the promise to meet the needs of first year distance students is the synchronous online classroom. Teacher practice as they transition from face to face to distance environments is influenced by their private theories about technology and pedagogy. Any limitations posed by these private theories may limit in turn the technological, pedagogical and content knowledge of the teachers – TPACK. This paper reports on the case of a regional university as it transitions to online, distance learning in the first year context, with a particular focus on pedagogy in the online classroom. It contributes to the first year pedagogy literature by considering the influences of existing practice of university teachers in the transition to distance learning with a particular focus on synchronous web-based tutorials. It provides recommendations to other institutions in terms of transition strategies, the pedagogical and learning benefits that are enabled and professional development needs of teachers. Normal 0 false false false EN-AU ZH-CN X-NONE

  6. Adaptive Tutorials Versus Web-Based Resources in Radiology: A Mixed Methods Comparison of Efficacy and Student Engagement.

    Science.gov (United States)

    Wong, Vincent; Smith, Ariella J; Hawkins, Nicholas J; Kumar, Rakesh K; Young, Noel; Kyaw, Merribel; Velan, Gary M

    2015-10-01

    Diagnostic imaging is under-represented in medical curricula globally. Adaptive tutorials, online intelligent tutoring systems that provide a personalized learning experience, have the potential to bridge this gap. However, there is limited evidence of their effectiveness for learning about diagnostic imaging. We performed a randomized mixed methods crossover trial to determine the impact of adaptive tutorials on perceived engagement and understanding of the appropriate use and interpretation of common diagnostic imaging investigations. Although concurrently engaged in disparate blocks of study, 99 volunteer medical students (from years 1-4 of the 6-year program) were randomly allocated to one of two groups. In the first arm of the trial on chest X-rays, one group received access to an adaptive tutorial, whereas the other received links to an existing peer-reviewed Web resource. These two groups crossed over in the second arm of the trial, which focused on computed tomography scans of the head, chest, and abdomen. At the conclusion of each arm of the trial, both groups completed an examination-style assessment, comprising questions both related and unrelated to the topics covered by the relevant adaptive tutorial. Online questionnaires were used to evaluate student perceptions of both learning resources. In both arms of the trial, the group using adaptive tutorials obtained significantly higher assessment scores than controls. This was because of higher assessment scores by senior students in the adaptive tutorial group when answering questions related to topics covered in those tutorials. Furthermore, students indicated significantly better engagement with adaptive tutorials than the Web resource and rated the tutorials as a significantly more valuable tool for learning. Medical students overwhelmingly accept adaptive tutorials for diagnostic imaging. The tutorials significantly improve the understanding of diagnostic imaging by senior students. Crown Copyright

  7. Video Tutorial of Continental Food

    Science.gov (United States)

    Nurani, A. S.; Juwaedah, A.; Mahmudatussa'adah, A.

    2018-02-01

    This research is motivated by the belief in the importance of media in a learning process. Media as an intermediary serves to focus on the attention of learners. Selection of appropriate learning media is very influential on the success of the delivery of information itself both in terms of cognitive, affective and skills. Continental food is a course that studies food that comes from Europe and is very complex. To reduce verbalism and provide more real learning, then the tutorial media is needed. Media tutorials that are audio visual can provide a more concrete learning experience. The purpose of this research is to develop tutorial media in the form of video. The method used is the development method with the stages of analyzing the learning objectives, creating a story board, validating the story board, revising the story board and making video tutorial media. The results show that the making of storyboards should be very thorough, and detailed in accordance with the learning objectives to reduce errors in video capture so as to save time, cost and effort. In video capturing, lighting, shooting angles, and soundproofing make an excellent contribution to the quality of tutorial video produced. In shooting should focus more on tools, materials, and processing. Video tutorials should be interactive and two-way.

  8. Robust Timing Synchronization in Aeronautical Mobile Communication Systems

    Science.gov (United States)

    Xiong, Fu-Qin; Pinchak, Stanley

    2004-01-01

    This work details a study of robust synchronization schemes suitable for satellite to mobile aeronautical applications. A new scheme, the Modified Sliding Window Synchronizer (MSWS), is devised and compared with existing schemes, including the traditional Early-Late Gate Synchronizer (ELGS), the Gardner Zero-Crossing Detector (GZCD), and the Sliding Window Synchronizer (SWS). Performance of the synchronization schemes is evaluated by a set of metrics that indicate performance in digital communications systems. The metrics are convergence time, mean square phase error (or root mean-square phase error), lowest SNR for locking, initial frequency offset performance, midstream frequency offset performance, and system complexity. The performance of the synchronizers is evaluated by means of Matlab simulation models. A simulation platform is devised to model the satellite to mobile aeronautical channel, consisting of a Quadrature Phase Shift Keying modulator, an additive white Gaussian noise channel, and a demodulator front end. Simulation results show that the MSWS provides the most robust performance at the cost of system complexity. The GZCD provides a good tradeoff between robustness and system complexity for communication systems that require high symbol rates or low overall system costs. The ELGS has a high system complexity despite its average performance. Overall, the SWS, originally designed for multi-carrier systems, performs very poorly in single-carrier communications systems. Table 5.1 in Section 5 provides a ranking of each of the synchronization schemes in terms of the metrics set forth in Section 4.1. Details of comparison are given in Section 5. Based on the results presented in Table 5, it is safe to say that the most robust synchronization scheme examined in this work is the high-sample-rate Modified Sliding Window Synchronizer. A close second is its low-sample-rate cousin. The tradeoff between complexity and lowest mean-square phase error determines

  9. Contraction theory based adaptive synchronization of chaotic systems

    International Nuclear Information System (INIS)

    Sharma, B.B.; Kar, I.N.

    2009-01-01

    Contraction theory based stability analysis exploits the incremental behavior of trajectories of a system with respect to each other. Application of contraction theory provides an alternative way for stability analysis of nonlinear systems. This paper considers the design of a control law for synchronization of certain class of chaotic systems based on backstepping technique. The controller is selected so as to make the error dynamics between the two systems contracting. Synchronization problem with and without uncertainty in system parameters is discussed and necessary stability proofs are worked out using contraction theory. Suitable adaptation laws for unknown parameters are proposed based on the contraction principle. The numerical simulations verify the synchronization of the chaotic systems. Also parameter estimates converge to their true values with the proposed adaptation laws.

  10. Implementation of a web-based, interactive polytrauma tutorial in computed tomography for radiology residents: How we do it

    International Nuclear Information System (INIS)

    Schlorhaufer, C.; Behrends, M.; Diekhaus, G.; Keberle, M.; Weidemann, J.

    2012-01-01

    Purpose: Due to the time factor in polytraumatized patients all relevant pathologies in a polytrauma computed tomography (CT) scan have to be read and communicated very quickly. During radiology residency acquisition of effective reading schemes based on typical polytrauma pathologies is very important. Thus, an online tutorial for the structured diagnosis of polytrauma CT was developed. Materials and methods: Based on current multimedia theories like the cognitive load theory a didactic concept was developed. As a web-environment the learning management system ILIAS was chosen. CT data sets were converted into online scrollable QuickTime movies. Audiovisual tutorial movies with guided image analyses by a consultant radiologist were recorded. Results: The polytrauma tutorial consists of chapterized text content and embedded interactive scrollable CT data sets. Selected trauma pathologies are demonstrated to the user by guiding tutor movies. Basic reading schemes are communicated with the help of detailed commented movies of normal data sets. Common and important pathologies could be explored in a self-directed manner. Conclusions: Ambitious didactic concepts can be supported by a web based application on the basis of cognitive load theory and currently available software tools.

  11. Implementation of a web-based, interactive polytrauma tutorial in computed tomography for radiology residents: How we do it

    Energy Technology Data Exchange (ETDEWEB)

    Schlorhaufer, C., E-mail: Schlorhaufer.Celia@mh-hannover.de [Department of Diagnostic and Interventional Radiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover (Germany); Behrends, M., E-mail: behrends.marianne@mh-hannover.de [Peter L. Reichertz Department of Medical Informatics, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover (Germany); Diekhaus, G., E-mail: Diekhaus.Gesche@mh-hannover.de [Department of Diagnostic and Interventional Radiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover (Germany); Keberle, M., E-mail: m.keberle@bk-paderborn.de [Department of Diagnostic and Interventional Radiology, Brüderkrankenhaus St. Josef Paderborn, Husener Str. 46, 33098 Paderborn (Germany); Weidemann, J., E-mail: Weidemann.Juergen@mh-hannover.de [Department of Diagnostic and Interventional Radiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover (Germany)

    2012-12-15

    Purpose: Due to the time factor in polytraumatized patients all relevant pathologies in a polytrauma computed tomography (CT) scan have to be read and communicated very quickly. During radiology residency acquisition of effective reading schemes based on typical polytrauma pathologies is very important. Thus, an online tutorial for the structured diagnosis of polytrauma CT was developed. Materials and methods: Based on current multimedia theories like the cognitive load theory a didactic concept was developed. As a web-environment the learning management system ILIAS was chosen. CT data sets were converted into online scrollable QuickTime movies. Audiovisual tutorial movies with guided image analyses by a consultant radiologist were recorded. Results: The polytrauma tutorial consists of chapterized text content and embedded interactive scrollable CT data sets. Selected trauma pathologies are demonstrated to the user by guiding tutor movies. Basic reading schemes are communicated with the help of detailed commented movies of normal data sets. Common and important pathologies could be explored in a self-directed manner. Conclusions: Ambitious didactic concepts can be supported by a web based application on the basis of cognitive load theory and currently available software tools.

  12. Learning from tutorials: a qualitative study of approaches to learning and perceptions of tutorial interaction

    DEFF Research Database (Denmark)

    Herrmann, Kim Jesper

    2014-01-01

    This study examines differences in university students’ approaches to learning when attending tutorials as well as variation in students’ perceptions of tutorials as an educational arena. In-depth qualitative analysis of semi-structured interviews with undergraduates showed how surface and deep...... approaches to learning were revealed in the students’ note-taking, listening, and engaging in dialogue. It was also shown how variation in the students’ approaches to learning were coherent with variation in the students’ perceptions of the tutors’ pedagogical role, the value of peer interaction......, and the overall purpose of tutorials. The results are discussed regarding the paradox that students relying on surface approaches to learning seemingly are the ones least likely to respond to tutorials in the way they were intended....

  13. Context-Based Synchronization of Concurrent Process Using Aspect ...

    African Journals Online (AJOL)

    ... will not cause any race condition if all other threads are accessing from the same context. The result of our experiment shows that context-based synchronization performs better than Java given the same number of threads. Keywords: Aspect-oriented programming, synchronization, resource, and concurrent process.

  14. The "magic" of tutorial centres in Hong Kong: An analysis of media marketing and pedagogy in a tutorial centre

    Science.gov (United States)

    Koh, Aaron

    2014-12-01

    Why do more than three-quarters of Hong Kong's senior secondary students flock to tutorial centres like moths to light? What is the "magic" that is driving the popularity of the tutorial centre enterprise? Indeed, looking at the ongoing boom of tutorial centres in Hong Kong (there are almost 1,000 of them), it is difficult not to ask these questions. This paper examines the phenomenon of tutorial centres in Hong Kong and seeks to understand what draws students to these centres. Combining theories of marketing semiotics and emotion studies, the author investigates the pivotal role of media marketing in generating the "magic" of tutorial centres, whose advertising strategy includes, for example, a display of billboard posters featuring stylishly-dressed "celebrity teachers". The author reviews some of the literature available on the subject of tutorial centres. In a case study approach, he then maps out the pedagogy he observed in an English tutorial class, seeking heuristic insights into the kind of teaching students in the study were looking for. He argues that part of the "magical" attraction of what are essentially "cram schools" is their formulaic pedagogy of teaching and reinforcing exam skills. Finally, the paper considers the social implications of the tutorial centre industry in terms of media marketing of education and unequal access to tutorial services.

  15. A proportional integral estimator-based clock synchronization protocol for wireless sensor networks.

    Science.gov (United States)

    Yang, Wenlun; Fu, Minyue

    2017-11-01

    Clock synchronization is an issue of vital importance in applications of WSNs. This paper proposes a proportional integral estimator-based protocol (EBP) to achieve clock synchronization for wireless sensor networks. As each local clock skew gradually drifts, synchronization accuracy will decline over time. Compared with existing consensus-based approaches, the proposed synchronization protocol improves synchronization accuracy under time-varying clock skews. Moreover, by restricting synchronization error of clock skew into a relative small quantity, it could reduce periodic re-synchronization frequencies. At last, a pseudo-synchronous implementation for skew compensation is introduced as synchronous protocol is unrealistic in practice. Numerical simulations are shown to illustrate the performance of the proposed protocol. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  16. Quantum synchronization in an optomechanical system based on Lyapunov control.

    Science.gov (United States)

    Li, Wenlin; Li, Chong; Song, Heshan

    2016-06-01

    We extend the concepts of quantum complete synchronization and phase synchronization, which were proposed in A. Mari et al., Phys. Rev. Lett. 111, 103605 (2013)PRLTAO0031-900710.1103/PhysRevLett.111.103605, to more widespread quantum generalized synchronization. Generalized synchronization can be considered a necessary condition or a more flexible derivative of complete synchronization, and its criterion and synchronization measure are proposed and analyzed in this paper. As examples, we consider two typical generalized synchronizations in a designed optomechanical system. Unlike the effort to construct a special coupling synchronization system, we purposefully design extra control fields based on Lyapunov control theory. We find that the Lyapunov function can adapt to more flexible control objectives, which is more suitable for generalized synchronization control, and the control fields can be achieved simply with a time-variant voltage. Finally, the existence of quantum entanglement in different generalized synchronizations is also discussed.

  17. Bus Based Synchronization Method for CHIPPER Based NoC

    Directory of Open Access Journals (Sweden)

    D. Muralidharan

    2016-01-01

    Full Text Available Network on Chip (NoC reduces the communication delay of System on Chip (SoC. The main limitation of NoC is power consumption and area overhead. Bufferless NoC reduces the area complexity and power consumption by eliminating buffers in the traditional routers. The bufferless NoC design should include live lock freeness since they use hot potato routing. This increases the complexity of bufferless NoC design. Among the available propositions to reduce this complexity, CHIPPER based bufferless NoC is considered as one of the best options. Live lock freeness is provided in CHIPPER through golden epoch and golden packet. All routers follow some synchronization method to identify a golden packet. Clock based method is intuitively followed for synchronization in CHIPPER based NoCs. It is shown in this work that the worst-case latency of packets is unbearably high when the above synchronization is followed. To alleviate this problem, broadcast bus NoC (BBus NoC approach is proposed in this work. The proposed method decreases the worst-case latency of packets by increasing the golden epoch rate of CHIPPER.

  18. An in-depth study of undergraduate tutorial system based on education and teaching integration reform

    Directory of Open Access Journals (Sweden)

    Fan Wenhui

    2016-01-01

    Full Text Available As personalized development for undergraduate is the trend of higher education development, the undergraduate tutors should play their role in the establishment of personalized personnel training mode. Based on reform practice of university education integration, this article gives a deepening research on the essence and implement methods of undergraduate tutorial system. To implement and strengthen the function of undergraduate tutorial system, we need to increase teachers’ comprehensive quality training, build a multiple-dimension, full-process and whole-staff-participation educational concept, absorb the enterprise mentors to give guidance on students’ career planning and implement the scientific and reasonable undergraduate administrative evaluation system. With continuous theory exploration and practice research, the quality of undergraduate talent training has been gradually improved.

  19. Review of available synchronization and time distribution techniques

    Science.gov (United States)

    Hall, R. G.; Lieberman, T. N.; Stone, R. R.

    1974-01-01

    The methods of synchronizing precision clocks will be reviewed placing particular attention to the simpler techniques, their accuracies, and the approximate cost of equipment. The more exotic methods of synchronization are discussed in lesser detail. The synchronization techniques that will be covered will include satellite dissemination, communication and navigation transmissions via VLF, LF, HF, UHF and microwave as well as commercial and armed forces television. Portable clock trips will also be discussed.

  20. Replacement of traditional lectures with computer-based tutorials: a case study

    Directory of Open Access Journals (Sweden)

    Derek Lavelle

    1996-12-01

    Full Text Available This paper reports on a pilot project with a group of 60 second-year undergraduates studying the use of standard forms of contract in the construction industry. The project entailed the replacement of two of a series of nine scheduled lectures with a computer-based tutorial. The two main aims of the project were to test the viability of converting existing lecture material into computer-based material on an in-house production basis, and to obtain feedback from the student cohort on their behavioural response to the change in media. The effect on student performance was not measured at this stage of development.

  1. Recently Published Lectures and Tutorials for ATLAS

    CERN Multimedia

    Herr, J.

    2006-01-01

    As reported in the September 2004 ATLAS eNews, the Web Lecture Archive Project, WLAP, a collaboration between the University of Michigan and CERN, has developed a synchronized system for recording and publishing educational multimedia presentations, using the Web as medium. This year, the University of Michigan team has been asked to record and publish all ATLAS Plenary sessions, as well as a large number of Physics and Computing tutorials. A significant amount of this material has already been published and can be accessed via the links below. The WLAP model is spreading. This summer, the CERN's High School Teachers program has used WLAP's system to record several physics lectures directed toward a broad audience. And a new project called MScribe, which is essentially the WLAP system coupled with an infrared tracking camera, is being used by the University of Michigan to record several University courses this academic year. All lectures can be viewed on any major platform with any common internet browser...

  2. Recently Published Lectures and Tutorials for ATLAS

    CERN Multimedia

    J. Herr

    2006-01-01

    As reported in the September 2004 ATLAS eNews, the Web Lecture Archive Project, a collaboration between the University of Michigan and CERN, has developed a synchronized system for recording and publishing educational multimedia presentations, using the Web as medium. The current system, including future developments for the project and the field in general, was recently presented at the CHEP 2006 conference in Mumbai, India. The relevant presentations and papers can be found here: The Web Lecture Archive Project A Web Lecture Capture System with Robotic Speaker Tracking This year, the University of Michigan team has been asked to record and publish all ATLAS Plenary sessions, as well as a large number of Physics and Computing tutorials. A significant amount of this material has already been published and can be accessed via the links below. All lectures can be viewed on any major platform with any common internet browser, either via streaming or local download (for limited bandwidth). Please enjoy the l...

  3. Recently Published Lectures and Tutorials for ATLAS

    CERN Multimedia

    Goldfarb, S.

    2006-01-01

    As reported in the September 2004 ATLAS eNews, the Web Lecture Archive Project, WLAP, a collaboration between the University of Michigan and CERN, has developed a synchronized system for recording and publishing educational multimedia presentations, using the Web as medium. The current system, including future developments for the project and the field in general, was recently presented at the CHEP 2006 conference in Mumbai, India. The relevant presentations and papers can be found here: The Web Lecture Archive Project. A Web Lecture Capture System with Robotic Speaker Tracking This year, the University of Michigan team has been asked to record and publish all ATLAS Plenary sessions, as well as a large number of Physics and Computing tutorials. A significant amount of this material has already been published and can be accessed via the links below. All lectures can be viewed on any major platform with any common internet browser, either via streaming or local download (for limited bandwidth). Please e...

  4. TMVA tutorial

    CERN Multimedia

    CERN. Geneva; VOSS, Helge

    2015-01-01

    This tutorial will both give an introduction on how to use TMVA in root6 and showcase some new features, such as modularity, variable importance, interfaces to R and python. After explaining the basic functionality, the typical steps required during a real life application (such as variable selection, pre-processing, tuning and classifier evaluation) will be demonstrated on simple examples. First part of the tutorial will use the usual Root interface (please make sure you have Root 6.04 installed somewhere). The second part will utilize the new server notebook functionality of Root as a Service. If you are within CERN but outside the venue or outside CERN please consult the notes attached.

  5. Community Earth System Model (CESM) Tutorial 2016 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Lamarque, Jean-Francois [Univ. Corporation for Atmospheric Research (UCAR) and National Center for Atmospheric Research (NCAR) and Climate and Global Dynamics Laboratory (CGD), Boulder, CO (United States)

    2017-05-09

    For the 2016 tutorial, NCAR/CGD requested a total budget of $70,000 split equally between DOE and NSF. The funds were used to support student participation (travel, lodging, per diem, etc.). Lectures and practical session support was primarily provided by local participants at no additional cost (see list below). The seventh annual Community Earth System Model (CESM) tutorial (2016) for students and early career scientists was held 8 – 12 August 2016. As has been the case over the last few years, this event was extremely successful and there was greater demand than could be met. There was continued interest in support of the NSF’s EaSM Infrastructure awards, to train these awardees in the application of the CESM. Based on suggestions from previous tutorial participants, the 2016 tutorial experience again provided direct connection to Yellowstone for each individual participant (rather than pairs), and used the NCAR Mesa Library. The 2016 tutorial included lectures on simulating the climate system and practical sessions on running CESM, modifying components, and analyzing data. These were targeted to the graduate student level. In addition, specific talks (“Application” talks) were introduced this year to provide participants with some in-depth knowledge of some specific aspects of CESM.

  6. Pinning synchronization of memristor-based neural networks with time-varying delays.

    Science.gov (United States)

    Yang, Zhanyu; Luo, Biao; Liu, Derong; Li, Yueheng

    2017-09-01

    In this paper, the synchronization of memristor-based neural networks with time-varying delays via pinning control is investigated. A novel pinning method is introduced to synchronize two memristor-based neural networks which denote drive system and response system, respectively. The dynamics are studied by theories of differential inclusions and nonsmooth analysis. In addition, some sufficient conditions are derived to guarantee asymptotic synchronization and exponential synchronization of memristor-based neural networks via the presented pinning control. Furthermore, some improvements about the proposed control method are also discussed in this paper. Finally, the effectiveness of the obtained results is demonstrated by numerical simulations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Precise Time Synchronisation and Ranging in Nano-Satellite Swarms

    Science.gov (United States)

    Laabs, Martin; Plettemeier, Dirk

    2015-04-01

    Precise time synchronization and ranging is very important for a variety of scientific experiments with more than two nano-satellites: For synthetic aperture radar (SAR) applications, for example, the radar signal phase (which corresponds to a synchronized time) as well as the location must be known on each satellite forming synthetic antenna. Also multi-static radar systems, MIMO radar systems or radio tomography applications will take advantage from highly accurate synchronization and position determination. We propose a method for synchronizing the time as well as measuring the distance between nano-satellites very precisely by utilizing mm-wave radio links. This approach can also be used for time synchronization of more than two satellites and accordingly determinating the precise relative location of nano-satellites in space. The time synchronization signal is modulated onto a mm-wave carrier. In the simplest form it is a harmonic sinusoidal signal with a frequency in the MHz range. The distance is measured with a frequency sweep or short pulse modulated onto a different carrier frequency. The sweep or pulse transmission start is synchronized to the received time synchronization. The time synchronization transmitter receives the pulse/sweep signal and can calculate the (double) time of flight for both signals. This measurement can be easily converted to the distance. The use of a mm-wave carrier leads to small antennas and the free space loss linked to the high frequency reduces non line of sight echoes. It also allows a high sweep/pulse bandwidth enabling superior ranging accuracy. Additionally, there is also less electromagnetic interference probability since telemetry and scientific applications typically do not use mm-wavefrequencies. Since the system is working full-duplex the time synchronization can be performed continuously and coherently. Up to now the required semiconductor processes did not achieve enough gain/bandwidth to realize this concept at

  8. The undergraduate physics tutorial program at CSU Los Angeles assessment of utility and areas of interest

    Science.gov (United States)

    Avetyan, Smbat

    The Physics Education Research (PER) group at the University of Washington have researched traditional teaching methods and found that students in introductory physics are lacking a conceptual understanding of the physics material. The solution they put forth is an interactive tutorial program designed to meet the lack of conceptual understanding. Since the tutorial programs inception at CSU Los Angeles in Fall 2006 no evaluation has been successfully undertaken therefore the effect of the tutorial program in the physics 200 series is deeply obscure to the department. The research has shed light on the tutorial program and brought into context its effectiveness on the overall physics 200 series courses at CSU Los Angeles. The researcher has addressed the following research questions, what overall effect does the tutorial program have on the Physics 200 series curriculum? What is the size and significance of gains attributable to the undergraduate calculus based Physics 200 series tutorial program at CSU Los Angeles? What can we learn from gains about individual weekly lessons from the Physics 200 series tutorial courses? What is the correlation of tutorial gains with student final course grades? Are the gains from the tutorial program different for genders? Is there a difference in gains based on the different students' colleges?

  9. Success of the Tutorial Program in Biochemistry at The Federal University of Vi

    Directory of Open Access Journals (Sweden)

    M.C. Baracat-Pereira

    2004-05-01

    Full Text Available Institutionalized at UFV in 2001, the Tutorial Program in Biochemistry aims to reduce the une-venness of basic prior knowledge among the students enrolled in regular Biochemistry courses. Thework methodology has been periodically evaluated and rened in order to overcome identied pro-blems. Thus, the objective of this study was to evaluate the Tutorial Program based on the stu-dentsachievement, to show implemented modications and proposed alternatives to adjust methodo-logies. The student-nal-grades were obtained from UFV les. Questionnaires were applied to thePrograms students at the end of each semester. Suggestions and criticism from tutors and coordinatingprofessors were discussed at weekly meetings. Along six semesters (2001-2003, a leveling o of thetutorial students was observed with the attending students (S, minimum of 75% attendance, averagegrade 71.3 that got grades close to the average of no-tutorial students (average grade 71.5. For thetutorial students with attendance below the required minimum (N, the average grade was 58.8. Thefailure rate for grade S students (7.4% was lower then that for no-tutorial students (9.9% and forgrade N students (27.9%. Based on the lled out questionnaire from tutorial students, we observeas follows: 96.7% stated that it is eective to participate in the Program and 79.9% modied theirstudy approach. Among the modications implemented in the Program, are as folows: 1 Increase inthe number of tutorial groups (from 4 to 6; 2 Reduction in the number of volunteer-students, givingpriority to students with decient prior knowledge in pre-requisite-disciplines; and 3 Time reductionof tutorial sessions (from 3 to 2h weekly, with smaller groups and exercise classes. Thus, the observedmotivation, the leveling o and the lower failure rate of the S grade tutorial students indicated that theTutorial Program at UFV is improving and reaching its objectives.

  10. Tutorial: Digital microfluidic biochips: Towards hardware/software co-design and cyber-physical system integration

    DEFF Research Database (Denmark)

    Ho, Tsung-Yi; Huang, Juinn-Dar; Pop, Paul

    2013-01-01

    This tutorial will first provide an overview of typical bio-molecular applications (market drivers) such as immunoassays, DNA sequencing, clinical chemistry, etc. Next, microarrays and various microfluidic platforms will be discussed. The next part of the tutorial will focus on electro-wetting-ba......This tutorial will first provide an overview of typical bio-molecular applications (market drivers) such as immunoassays, DNA sequencing, clinical chemistry, etc. Next, microarrays and various microfluidic platforms will be discussed. The next part of the tutorial will focus on electro......-wetting-based digital micro-fluidic biochips. The key idea here is to manipulate liquids as discrete droplets. A number of case studies based on representative assays and laboratory procedures will be interspersed in appropriate places throughout the tutorial. Basic concepts in micro-fabrication techniques will also...... be discussed. Attendees will next learn about CAD and reconfiguration aspects of digital microfluidic biochips. Synthesis tools will be described to map assay protocols from the lab bench to a droplet-based microfluidic platform and generate an optimized schedule of bioassay operations, the binding of assay...

  11. The Impact of Library Tutorials on the Information Literacy Skills of Occupational Therapy and Physical Therapy Students in an Evidence-Based Practice Course: A Rubric Assessment.

    Science.gov (United States)

    Schweikhard, April J; Hoberecht, Toni; Peterson, Alyssa; Randall, Ken

    2018-01-01

    This study measures how online library instructional tutorials implemented into an evidence-based practice course have impacted the information literacy skills of occupational and physical therapy graduate students. Through a rubric assessment of final course papers, this study compares differences in students' search strategies and cited sources pre- and post-implementation of the tutorials. The population includes 180 randomly selected graduate students from before and after the library tutorials were introduced into the course curriculum. Results indicate a statistically significant increase in components of students' searching skills and ability to find higher levels of evidence after completing the library tutorials.

  12. Advanced satellite servicing facility studies

    Science.gov (United States)

    Qualls, Garry D.; Ferebee, Melvin J., Jr.

    1988-01-01

    A NASA-sponsored systems analysis designed to identify and recommend advanced subsystems and technologies specifically for a manned Sun-synchronous platform for satellite management is discussed. An overview of system design, manned and unmanned servicing facilities, and representative mission scenarios are given. Mission areas discussed include facility based satellite assembly, checkout, deployment, refueling, repair, and systems upgrade. The ferrying of materials and consumables to and from manufacturing platforms, deorbit, removal, repositioning, or salvage of satellites and debris, and crew rescue of any other manned vehicles are also examined. Impacted subsytems discussed include guidance navigation and control, propulsion, data management, power, thermal control, structures, life support, and radiation management. In addition, technology issues which would have significant impacts on the system design are discussed.

  13. Chaos synchronization basing on symbolic dynamics with nongenerating partition.

    Science.gov (United States)

    Wang, Xingyuan; Wang, Mogei; Liu, Zhenzhen

    2009-06-01

    Using symbolic dynamics and information theory, we study the information transmission needed for synchronizing unidirectionally coupled oscillators. It is found that when sustaining chaos synchronization with nongenerating partition, the synchronization error will be larger than a critical value, although the required coupled channel capacity can be smaller than the case of using a generating partition. Then we show that no matter whether a generating or nongenerating partition is in use, a high-quality detector can guarantee the lead of the response oscillator, while the lag responding can make up the low precision of the detector. A practicable synchronization scheme basing on a nongenerating partition is also proposed in this paper.

  14. Synchronous message-based communication for distributed heterogeneous systems

    International Nuclear Information System (INIS)

    Wilkinson, N.; Dohan, D.

    1992-01-01

    The use of a synchronous, message-based real-time operating system (Unison) as the basis of transparent interprocess and inter-processor communication over VME-bus is described. The implementation of a synchronous, message-based protocol for network communication between heterogeneous systems is discussed. In particular, the design and implementation of a message-based session layer over a virtual circuit transport layer protocol using UDP/IP is described. Inter-process communication is achieved via a message-based semantic which is portable by virtue of its ease of implementation in other operating system environments. Protocol performance for network communication among heterogeneous architecture is presented, including VMS, Unix, Mach and Unison. (author)

  15. OAI-PMH basics Tutorial 3

    CERN Document Server

    CERN. Geneva

    2007-01-01

    This tutorial is aimed at those who are new to the area of repositories and who want to learn more about key advocacy and policy issues. The tutorial will include information and advice on putting together an institutional advocacy campaign and developing policies for your repository. There will be opportunities for participants to share experiences and to ask questions. The tutorial will include a practical exercise in developing an advocacy presentation. Participants with experience of advocacy are welcome to attend the session to share their experiences, but should bear in mind that it is aimed primarily at those looking for help and advice in advocacy matters.

  16. Proposal for tutorial: Resilience in carrier Ethernet transport

    DEFF Research Database (Denmark)

    Berger, Michael Stübert; Wessing, Henrik; Ruepp, Sarah Renée

    2009-01-01

    This tutorial addresses how Carrier Ethernet technologies can be used in the transport network to provide resilience to the packet layer. Carrier Ethernet networks based on PBB-TE and T-MPLS/MPLS-TP are strong candidates for reliable transport of triple-play services. These technologies offer...... of enhancements are still required to make Carrier Ethernet ready for large scale deployments of reliable point-to-multipoint services. The tutorial highlights the necessary enhancements and shows possible solutions and directions towards reliable multicast. Explicit focus is on OAM for multicast, where...

  17. Karibu Tutorials

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    These tutorials demonstrate how to use Karibu for high quality data collection, in particular how to setup a distributed Karibu system and how to adapt Karibu to your particular data collection needs....

  18. Assessing the flexibility of research-based instructional strategies: Implementing tutorials in introductory physics in the lecture environment

    Science.gov (United States)

    Kryjevskaia, Mila; Boudreaux, Andrew; Heins, Dustin

    2014-03-01

    Materials from Tutorials in Introductory Physics, originally designed and implemented by the Physics Education Group at the University of Washington, were used in modified form as interactive lectures under conditions significantly different from those suggested by the curriculum developers. Student learning was assessed using tasks drawn from the physics education research literature. Use of tutorials in the interactive lecture format yielded gains in student understanding comparable to those obtained through the canonical tutorial implementation at the University of Washington, suggesting that student engagement with the intellectual steps laid out in the tutorials, rather than the specific strategies used in facilitating such engagement, plays the central role in promoting student learning. We describe the implementation details and assessment of student learning for two different tutorials: one focused on mechanical waves, used at North Dakota State University, and one on Galilean relativity, used at Western Washington University. Also discussed are factors that may limit the generalizability of the results.

  19. Linear Matrix Inequality Based Fuzzy Synchronization for Fractional Order Chaos

    Directory of Open Access Journals (Sweden)

    Bin Wang

    2015-01-01

    Full Text Available This paper investigates fuzzy synchronization for fractional order chaos via linear matrix inequality. Based on generalized Takagi-Sugeno fuzzy model, one efficient stability condition for fractional order chaos synchronization or antisynchronization is given. The fractional order stability condition is transformed into a set of linear matrix inequalities and the rigorous proof details are presented. Furthermore, through fractional order linear time-invariant (LTI interval theory, the approach is developed for fractional order chaos synchronization regardless of the system with uncertain parameters. Three typical examples, including synchronization between an integer order three-dimensional (3D chaos and a fractional order 3D chaos, anti-synchronization of two fractional order hyperchaos, and the synchronization between an integer order 3D chaos and a fractional order 4D chaos, are employed to verify the theoretical results.

  20. Satellite-Based Sunshine Duration for Europe

    Directory of Open Access Journals (Sweden)

    Bodo Ahrens

    2013-06-01

    Full Text Available In this study, two different methods were applied to derive daily and monthly sunshine duration based on high-resolution satellite products provided by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT Satellite Application Facility on Climate Monitoring using data from Meteosat Second Generation (MSG SEVIRI (Spinning Enhanced Visible and Infrared Imager. The satellite products were either hourly cloud type or hourly surface incoming direct radiation. The satellite sunshine duration estimates were not found to be significantly different using the native 15-minute temporal resolution of SEVIRI. The satellite-based sunshine duration products give additional spatial information over the European continent compared with equivalent in situ-based products. An evaluation of the satellite sunshine duration by product intercomparison and against station measurements was carried out to determine their accuracy. The satellite data were found to be within ±1 h/day compared to high-quality Baseline Surface Radiation Network or surface synoptic observations (SYNOP station measurements. The satellite-based products differ more over the oceans than over land, mainly because of the treatment of fractional clouds in the cloud type-based sunshine duration product. This paper presents the methods used to derive the satellite sunshine duration products and the performance of the different retrievals. The main benefits and disadvantages compared to station-based products are also discussed.

  1. FPGA based fast synchronous serial multi-wire links synchronization

    Science.gov (United States)

    Pozniak, Krzysztof T.

    2013-10-01

    The paper debates synchronization method of multi-wire, serial link of constant latency, by means of pseudo-random numbers generators. The solution was designed for various families of FPGA circuits. There were debated synchronization algorithm and functional structure of parameterized transmitter and receiver modules. The modules were realized in VHDL language in a behavioral form.

  2. Quantitative Microbial Risk Assessment Tutorial - Primer

    Science.gov (United States)

    This document provides a Quantitative Microbial Risk Assessment (QMRA) primer that organizes QMRA tutorials. The tutorials describe functionality of a QMRA infrastructure, guide the user through software use and assessment options, provide step-by-step instructions for implementi...

  3. Design and Assessment of Online, Interactive Tutorials That Teach Science Process Skills.

    Science.gov (United States)

    Kramer, Maxwell; Olson, Dalay; Walker, J D

    2018-06-01

    Explicit emphasis on teaching science process skills leads to both gains in the skills themselves and, strikingly, deeper understanding of content. Here, we created and tested a series of online, interactive tutorials with the goal of helping undergraduate students develop science process skills. We designed the tutorials in accordance with evidence-based multimedia design principles and student feedback from usability testing. We then tested the efficacy of the tutorials in an introductory undergraduate biology class. On the basis of a multivariate ordinary least-squares regression model, students who received the tutorials are predicted to score 0.82 points higher on a 15-point science process skill assessment than their peers who received traditional textbook instruction on the same topic. This moderate but significant impact indicates that well-designed online tutorials can be more effective than traditional ways of teaching science process skills to undergraduate students. We also found trends that suggest the tutorials are especially effective for nonnative English-speaking students. However, due to a limited sample size, we were unable to confirm that these trends occurred due to more than just variation in the student group sampled.

  4. Image Blocking Encryption Algorithm Based on Laser Chaos Synchronization

    Directory of Open Access Journals (Sweden)

    Shu-Ying Wang

    2016-01-01

    Full Text Available In view of the digital image transmission security, based on laser chaos synchronization and Arnold cat map, a novel image encryption scheme is proposed. Based on pixel values of plain image a parameter is generated to influence the secret key. Sequences of the drive system and response system are pretreated by the same method and make image blocking encryption scheme for plain image. Finally, pixels position are scrambled by general Arnold transformation. In decryption process, the chaotic synchronization accuracy is fully considered and the relationship between the effect of synchronization and decryption is analyzed, which has characteristics of high precision, higher efficiency, simplicity, flexibility, and better controllability. The experimental results show that the encryption algorithm image has high security and good antijamming performance.

  5. Highly Accurate Timestamping for Ethernet-Based Clock Synchronization

    OpenAIRE

    Loschmidt, Patrick; Exel, Reinhard; Gaderer, Georg

    2012-01-01

    It is not only for test and measurement of great importance to synchronize clocks of networked devices to timely coordinate data acquisition. In this context the seek for high accuracy in Ethernet-based clock synchronization has been significantly supported by enhancements to the Network Time Protocol (NTP) and the introduction of the Precision Time Protocol (PTP). The latter was even applied to instrumentation and measurement applications through the introduction of LXI....

  6. Synchronization of metronomes

    Science.gov (United States)

    Pantaleone, James

    2002-10-01

    Synchronization is a common phenomenon in physical and biological systems. We examine the synchronization of two (and more) metronomes placed on a freely moving base. The small motion of the base couples the pendulums causing synchronization. The synchronization is generally in-phase, with antiphase synchronization occurring only under special conditions. The metronome system provides a mechanical realization of the popular Kuramoto model for synchronization of biological oscillators, and is excellent for classroom demonstrations and an undergraduate physics lab.

  7. Tutorials in endovascular neurosurgery and interventional neuroradiology

    International Nuclear Information System (INIS)

    Byrne, James Vincent

    2012-01-01

    This book aims to provide the trainee and practicing minimally invasive neurological therapist with a comprehensive understanding of the background science and theory that forms the foundation of their work. The contents are based on the tutorial teaching techniques used at the University of Oxford and are authored by the MSc Course Director. The tutorial is a learning episode focussed on a particular topic and intended to guide the student/reader through the background literature, to highlight the research on which standard practices are based and to provide the insights of an experienced practitioner. Each chapter of the book covers a different topic to build a complete review of the subspecialty, with in-depth discussion of all currently used techniques. The literature is reviewed and presented in context to illustrate its importance to the practice of this rapidly expanding field of medical treatment.

  8. Tutorials in endovascular neurosurgery and interventional neuroradiology

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, James Vincent [Univ. of Oxford, Oxford (United Kingdom). Dept. of Neuroradiology

    2012-07-01

    This book aims to provide the trainee and practicing minimally invasive neurological therapist with a comprehensive understanding of the background science and theory that forms the foundation of their work. The contents are based on the tutorial teaching techniques used at the University of Oxford and are authored by the MSc Course Director. The tutorial is a learning episode focussed on a particular topic and intended to guide the student/reader through the background literature, to highlight the research on which standard practices are based and to provide the insights of an experienced practitioner. Each chapter of the book covers a different topic to build a complete review of the subspecialty, with in-depth discussion of all currently used techniques. The literature is reviewed and presented in context to illustrate its importance to the practice of this rapidly expanding field of medical treatment.

  9. Indico MEETING tutorial

    CERN Multimedia

    CERN. Geneva; Manzoni, Alex Marc; Dimou, Maria

    2017-01-01

    This short tutorial explains how to create a MEETING in indico, how to populate the timetable, write minutes and how to add material. If you are only interested in the timetable part, please slide to 03.39, for the minutes to 07.46 and for adding material to 08.29.   Tell us what you think via e-learning.support at cern.ch More tutorials in the e-learning collection of the CERN Document Server (CDS) http://cds.cern.ch/collection/E-learning%20modules?ln=en All info about the CERN rapid e-learning project is linked from http://twiki.cern.ch/ELearning  

  10. RB Particle Filter Time Synchronization Algorithm Based on the DPM Model.

    Science.gov (United States)

    Guo, Chunsheng; Shen, Jia; Sun, Yao; Ying, Na

    2015-09-03

    Time synchronization is essential for node localization, target tracking, data fusion, and various other Wireless Sensor Network (WSN) applications. To improve the estimation accuracy of continuous clock offset and skew of mobile nodes in WSNs, we propose a novel time synchronization algorithm, the Rao-Blackwellised (RB) particle filter time synchronization algorithm based on the Dirichlet process mixture (DPM) model. In a state-space equation with a linear substructure, state variables are divided into linear and non-linear variables by the RB particle filter algorithm. These two variables can be estimated using Kalman filter and particle filter, respectively, which improves the computational efficiency more so than if only the particle filter was used. In addition, the DPM model is used to describe the distribution of non-deterministic delays and to automatically adjust the number of Gaussian mixture model components based on the observational data. This improves the estimation accuracy of clock offset and skew, which allows achieving the time synchronization. The time synchronization performance of this algorithm is also validated by computer simulations and experimental measurements. The results show that the proposed algorithm has a higher time synchronization precision than traditional time synchronization algorithms.

  11. Tutorials in university students with a disability

    Directory of Open Access Journals (Sweden)

    Joaquín Gairín Sallán

    2013-10-01

    Full Text Available This article places an emphasis on the importance of tutorials for students with a disability in universities. It presented the most significant results of the study of tutorials carried out in help services, units or offices for students with a disability inmore than 45 Spanish universities, in relation to promotion, reception, completion and graduation. The contributions highlight the importance of organising a response through a Tutorial Action Plan made up of the stages of motivation and awareness-raisin, planning, execution, evaluation and institutionalisation. Among the principle conclusions, the importance of moving towards a truly inclusive university through tutorial activity is highlighted, thereby providing a guide for providing assistance to university students with a disability.

  12. Progress Report--Microsoft Office 2003 Lynchburg College Tutorials

    Science.gov (United States)

    Murray, Tom

    2004-01-01

    For the past several years Lynchburg College has developed Microsoft tutorials for use with academic classes and faculty, student and staff training. The tutorials are now used internationally. Last year Microsoft and Verizon sponsored a tutorial web site at http://www.officetutorials.com. This website recognizes ASCUE members for their wonderful…

  13. Tutorial Instruction in Science Education

    Directory of Open Access Journals (Sweden)

    Rhea Miles

    2015-06-01

    Full Text Available The purpose of the study is to examine the tutorial practices of in-service teachers to address the underachievement in the science education of K-12 students. Method: In-service teachers in Virginia and North Carolina were given a survey questionnaire to examine how they tutored students who were in need of additional instruction. Results: When these teachers were asked, “How do you describe a typical one-on-one science tutorial session?” the majority of their responses were categorized as teacher-directed. Many of the teachers would provide a science tutorial session for a student after school for 16-30 minutes, one to three times a week. Respondents also indicated they would rely on technology, peer tutoring, scientific inquiry, or themselves for one-on-one science instruction. Over half of the in-service teachers that responded to the questionnaire stated that they would never rely on outside assistance, such as a family member or an after school program to provide tutorial services in science. Additionally, very few reported that they incorporated the ethnicity, culture, or the native language of ELL students into their science tutoring sessions.

  14. 14 CFR 141.91 - Satellite bases.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Satellite bases. 141.91 Section 141.91... OTHER CERTIFICATED AGENCIES PILOT SCHOOLS Operating Rules § 141.91 Satellite bases. The holder of a... assistant chief instructor is designated for each satellite base, and that assistant chief instructor is...

  15. Synchronization challenges in packet-based Cloud-RAN fronthaul for mobile networks

    DEFF Research Database (Denmark)

    Checko, Aleksandra; Juul, Anders Christian; Christiansen, Henrik Lehrmann

    2015-01-01

    In this paper, we look at reusing existing packet-based network (e.g. Ethernet) to possibly decrease deployment costs of fronthaul Cloud Radio Access Network (C-RAN) network and cost of Baseband Unit (BBU) resources. The challenge of this solution is that it requires mobile traffic (until now...... transmitted over synchronous protocols) to traverse the asynchronous Ethernet without losing synchronization. We analyze synchronization requirements of mobile networks and present an overview of solutions that fulfill them in traditional mobile networks. Then we elaborate on challenges that packet-based...... fronthaul imposes. We analyze possible contributions to frequency and phase error. We verify the feasibility of using the IEEE 1588v2 also know as Precision Time Protocol (PTP) for providing accurate phase and frequency synchronization. The study is based on simulations made in OPNET modeler. Thereby we...

  16. An interactive tutorial on radiation protection for medical students

    International Nuclear Information System (INIS)

    Sendra-Portero, F.; Martinez-Morillo, M.

    2003-01-01

    The aim of this project is to develop an interactive tutorial designed for medical students training in radiation protection in order to use its definitive version in a collaborative group of medical schools. The contents of the tutorial matchers the outlines proposed by the EC guidelines on education and training in Radiation Protection for Medical exposures (RP118), for medical and dental schools. The tutorial is organised in virtual lectures, following a similar structure than the traditional lectures, slides and explanations. There is a central script for each theme with a forward-return interaction. Additionally, branches with deeper explanations (drawings, images, videos,...) are provided to the user. The tutorial is being developed on a set of power Point presentations, linked between them. The user can choose two ways sto launch each lecture, based either on spoken (audio) or written explanations. We present the initial version of a useful tool for pre-graduate training of general practitioners in Radiation Protection, which is a complementary tool for personally adapted computed-based education. Most of the contents can be easily adapted for other students of health related careers (i. e. nurses, technologists...) The use of multimedia tools has been recommended in the field of radiation protection, but developing these tools is time consuming and needs expertise in both, educative and multimedia resources. This projects takes part of more than a dozen multimedia projects on different radiology related subjects developed in our department. (Author) 6 refs

  17. Defense Meteorological Satellite Program (DMSP) - Space Weather Sensors

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Defense Meteorological Satellite Program (DMSP) maintains a constellation of sun-synchronous, near-polar orbiting satellites. The orbital period is 101 minutes...

  18. Synchronization and anti-synchronization coexist in Chen-Lee chaotic systems

    International Nuclear Information System (INIS)

    Chen, J.-H.; Chen, H.-K.; Lin, Y.-K.

    2009-01-01

    This study demonstrates that synchronization and anti-synchronization can coexist in Chen-Lee chaotic systems by direct linear coupling. Based on Lyapunov's direct method, a linear controller was designed to assure that two different types of synchronization can simultaneously be achieved. Further, the hybrid projective synchronization of Chen-Lee chaotic systems was studied using a nonlinear control scheme. The nonlinear controller was designed according to the Lyapunov stability theory to guarantee the hybrid projective synchronization, including synchronization, anti-synchronization, and projective synchronization. Finally, numerical examples are presented in order to illustrate the proposed synchronization approach.

  19. Prevalence and prognosis of synchronous colorectal cancer: a Dutch population-based study

    NARCIS (Netherlands)

    Mulder, S.F.; Kranse, R.; Damhuis, R.A.; Wilt, J.H. de; Ouwendijk, R.J.; Kuipers, E.J.; Leerdam, M.E. van

    2011-01-01

    BACKGROUND: A noticeable proportion of colorectal cancer (CRC) patients are diagnosed with synchronous CRC. Large population-based studies on the incidence, risk factors and prognosis of synchronous CRC are, however, scarce, and are needed for better determination of risks of synchronous CRC in

  20. Tutorials in university students with a disability

    OpenAIRE

    Joaquín Gairín Sallán; José Luís Muñoz Moreno

    2013-01-01

    This article places an emphasis on the importance of tutorials for students with a disability in universities. It presented the most significant results of the study of tutorials carried out in help services, units or offices for students with a disability inmore than 45 Spanish universities, in relation to promotion, reception, completion and graduation. The contributions highlight the importance of organising a response through a Tutorial Action Plan made up of the stages of motivation and ...

  1. NVidia Tutorial

    CERN Document Server

    CERN. Geneva; MESSMER, Peter; DEMOUTH, Julien

    2015-01-01

    This tutorial will present Caffee, a powerful Python library to implement solutions working on CPUs and GPUs, and explain how to use it to build and train Convolutional Neural Networks using NVIDIA GPUs. The session requires no prior experience with GPUs or Caffee.

  2. Exploring the Relationships between Web Usability and Students' Perceived Learning in Web-Based Multimedia (WBMM) Tutorials

    Science.gov (United States)

    Mackey, Thomas P.; Ho, Jinwon

    2008-01-01

    The purpose of this case study is to better understand the relationships between Web usability and students' perceived learning in the design and implementation of Web-based multimedia (WBMM) tutorials in blended courses. Much of the current research in this area focuses on the use of multimedia as a replacement for classroom instruction rather…

  3. Interactive, Web-based Information Skills Tutorial Well Received by Graduate Students in Health and Social Care Research. A review of: Grant, Maria J., and Alison J. Brettle. “Developing and Evaluating an Interactive Information Skills Tutorial.” Health Information and Libraries Journal 23.2 (June 2006: 79 ‐86.

    Directory of Open Access Journals (Sweden)

    Marcy L. Brown

    2007-03-01

    Full Text Available Objective – To determine whether a newly developed interactive, Web -based tutorial on OVID MEDLINE was acceptable to students, and to identify whether the tutorial improved students’ information skills. Design – Objective and subjective assessment within a small cohort study. Setting – An evidence based practice module within a Master's in Research (MRes program at the University of Salford, UK. Subjects – A total of 13 usable evaluations were received from graduate students who took an evidence based practice module as part of their MRes coursework. Methods – Information skills (IS were taught in weeks two and three of a 12 ‐week module on evidence based practice. Each of the two IS sessions lasted approximately three hours. At the beginning of the first session, baseline skills were assessed by asking the students to perform a literature search on either the effectiveness of nursing interventions for smoking cessation, or the effectiveness of rehabilitation after stroke. The OVID MEDLINE tutorial was introduced at the first session, and guided hands ‐on practice was offered. Homework was given, and between ‐session use of the tutorial was encouraged. At the end of the second session, students were asked to complete another search in order to assess short ‐term impact of the tutorial. Both sets of search results were scored using a checklist rubric that looked for Boolean operators, use of MeSH terms, use of limits, number and relevance of references, and other assessment criteria. The rubric was a modified version of a tool published by Rosenberg et al. The tutorial remained available throughout the 12 ‐week module, at which time a systematic literature review was assigned in order to measure longer ‐term impact. As an additional subjective measurement, a questionnaire regarding the information skills sessions and tutorial was given at the end of the second IS session (week 3. Main Results – Thirteen objective

  4. pFUnit 3.0 Tutorial Advanced

    Science.gov (United States)

    Clune, Tom

    2014-01-01

    This tutorial will introduce Fortran developers to unit-testing and test-driven development (TDD) using pFUnit. As with other unit-testing frameworks, pFUnit, simplifies the process of writing, collecting, and executing tests while providing clear diagnostic messages for failing tests. pFUnit specifically targets the development of scientific-technical software written in Fortran and includes customized features such as: assertions for multi-dimensional arrays, distributed (MPI) and thread-based (OpenMP) parallellism, and flexible parameterized tests.These sessions will include numerous examples and hands-on exercises that gradually build in complexity. Attendees are expected to have working knowledge of F90, but familiarity with object-oriented syntax in F2003 and MPI will be of benefit for the more advanced examples. By the end of the tutorial the audience should feel comfortable in applying pFUnit within their own development environment.

  5. Adaptive fuzzy bilinear observer based synchronization design for generalized Lorenz system

    International Nuclear Information System (INIS)

    Baek, Jaeho; Lee, Heejin; Kim, Seungwoo; Park, Mignon

    2009-01-01

    This Letter proposes an adaptive fuzzy bilinear observer (FBO) based synchronization design for generalized Lorenz system (GLS). The GLS can be described to TS fuzzy bilinear generalized Lorenz model (FBGLM) with their states immeasurable and their parameters unknown. We design an adaptive FBO based on TS FBGLM for synchronization. Lyapunov theory is employed to guarantee the stability of error dynamic system via linear matrix equalities (LMIs) and to derive the adaptive laws to estimate unknown parameters. Numerical example is given to demonstrate the validity of our proposed adaptive FBO approach for synchronization.

  6. Integrating Supplementary Application-Based Tutorials in the Multivariable Calculus Course

    Science.gov (United States)

    Verner, I. M.; Aroshas, S.; Berman, A.

    2008-01-01

    This article presents a study in which applications were integrated in the Multivariable Calculus course at the Technion in the framework of supplementary tutorials. The purpose of the study was to test the opportunity of extending the conventional curriculum by optional applied problem-solving activities and get initial evidence on the possible…

  7. Advocacy and policy issues Tutorial 2

    CERN Document Server

    CERN. Geneva

    2007-01-01

    This tutorial is aimed at those who are new to the area of repositories and who want to learn more about key advocacy and policy issues. The tutorial will include information and advice on putting together an institutional advocacy campaign and developing policies for your repository. There will be opportunities for participants to share experiences and to ask questions. The tutorial will include a practical exercise in developing an advocacy presentation. Participants with experience of advocacy are welcome to attend the session to share their experiences, but should bear in mind that it is aimed primarily at those looking for help and advice in advocacy matters.

  8. Solidaridad en la relación tutorial

    Directory of Open Access Journals (Sweden)

    Arturo G Rillo

    Full Text Available Introducción. La tutoría académica concreta el proceso educativo sustentado en estándares de calidad, características y necesidades de aprendizaje del estudiante; se desenvuelve confrontando actividades pedagógicas y consolida solidaridades. En este contexto, el estudio se realizó con el propósito de realizar la analítica de la solidaridad que surge de la relación tutorial. Método. Desde el ámbito de la hermenéutica, se realizó un estudio en cuatro fases: analítica, comprensiva, reconstructiva, crítica. Se construyó el concepto de solidaridad en la relación tutorial con propuestas de Gadamer, Habermas, Adela Cortina y Edgar Morín. Las categorías de análisis fueron: construcción social del sentido en la relación tutorial, relación tutorial de naturaleza epistémica, compleja, infinita y cambiante; y práctica tutorial generadora de solidaridades. Resultados. La solidaridad como praxis humana orientada al cuidado del otro (Fürsorge promueve el encuentro con el estudiante. La tutoría académica regula la experiencia vital de la dualidad enseñar-aprender; articula la decisión del docente y alumno con la responsabilidad solidaria. El docente concreta un asentimiento aconsejado por la amistad de estar-ahí-con el estudiante, acompañándolo, posibilitando elecciones y decisiones entre posibilidades para una vida sustentable mediante la virtud de la phrónesis. Conclusiones. La solidaridad en la relación tutorial como horizonte de sentido engarza la cosmovisión del binomio docente-estudiante en la relación tutorial. Dado el vínculo social, se ubica en el escenario de la relación tutorial el sentido originario de la amistad y la solidaridad con los siguientes baremos: compasión, saber hacer, confidencialidad, confianza, conciencia de sí mismo y del otro, tacto, escucha atenta y solícita, comprensión del otro.

  9. First year clinical tutorials: students’ learning experience

    Directory of Open Access Journals (Sweden)

    Burgess A

    2014-11-01

    Full Text Available Annette Burgess,1 Kim Oates,2 Kerry Goulston,2 Craig Mellis1 1Central Clinical School, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia; 2Sydney Medical School, The University of Sydney, Sydney, NSW, Australia Background: Bedside teaching lies at the heart of medical education. The learning environment afforded to students during clinical tutorials contributes substantially to their knowledge, thinking, and learning. Situated cognition theory posits that the depth and breadth of the students' learning experience is dependent upon the attitude of the clinical teacher, the structure of the tutorial, and the understanding of tutorial and learning objectives. This theory provides a useful framework to conceptualize how students' experience within their clinical tutorials impacts their knowledge, thinking, and learning. Methods: The study was conducted with one cohort (n=301 of students who had completed year 1 of the medical program at Sydney Medical School in 2013. All students were asked to complete a three-part questionnaire regarding their perceptions of their clinical tutor's attributes, the consistency of the tutor, and the best features of the tutorials and need for improvement. Both quantitative and qualitative data were collected and analyzed using descriptive statistics. Results: The response rate to the questionnaire was 88% (265/301. Students perceived that their tutors displayed good communication skills and enthusiasm, encouraged their learning, and were empathetic toward patients. Fifty-two percent of students reported having the same communications tutor for the entire year, and 28% reported having the same physical examination tutor for the entire year. Students would like increased patient contact, greater structure within their tutorials, and greater alignment of teaching with the curriculum. Conclusion: Situated cognition theory provides a valuable lens to view students' experience of learning within the

  10. Educational Tutorial Video with Aspects of Psychological Sensation and Perception in Academic Achievement

    Directory of Open Access Journals (Sweden)

    Martha Jiménez García

    2015-09-01

    Full Text Available In Mexico 75.5% of children and young students in elementary and secondary school are at insufficient and elementary levels in mathematics. The purpose of this research is to join the UNESCO initiative by granting quality education, boosted by technology (Rose, 2013. Specifically, the objective is to analyze the impact of using a tutorial video on academic achievement, based on Gestalt psychology stimulating the sensation and perception cognitive capabilities. Using a 50 student sample was used, which was divided into two groups (experimental and control we test whether students that use a tutorial video based on sensation and perception increase their attention and interest to increase academic achievement. The experimental group was a virtual class with tutorial videos on the use of slopes, explanation of the equation, and a virtual graph generator. Both groups were a survey and an exam. The results show that a high impact on the grades and on the perception of knowledge in the experimental group; the average academic achievement of the experimental group was 9.31, against 2 in the control group. Thus, we conclude that the tutorial video presented stimulates cognitive capabilities and improves academic achievement with a 7.3 impact per additional unit of tutorial video, presented as reinforcement of the class.

  11. Novel Fuzzy-Modeling-Based Adaptive Synchronization of Nonlinear Dynamic Systems

    Directory of Open Access Journals (Sweden)

    Shih-Yu Li

    2017-01-01

    Full Text Available In this paper, a novel fuzzy-model-based adaptive synchronization scheme and its fuzzy update laws of parameters are proposed to address the adaptive synchronization problem. The proposed fuzzy controller does not share the same premise of fuzzy system, and the numbers of fuzzy controllers is reduced effectively through the novel modeling strategy. In addition, based on the adaptive synchronization scheme, the error dynamic system can be guaranteed to be asymptotically stable and the true values of unknown parameters can be obtained. Two identical complicated dynamic systems, Mathieu-Van der pol system (M-V system with uncertainties, are illustrated for numerical simulation example to show the effectiveness and feasibility of the proposed novel adaptive control strategy.

  12. A Pilot Evaluation of a Tutorial to Teach Clients and Clinicians About Gambling Game Design.

    Science.gov (United States)

    Turner, Nigel E; Robinson, Janine; Harrigan, Kevin; Ferentzy, Peter; Jindani, Farah

    2018-01-01

    This paper describes the pilot evaluation of an Internet-based intervention, designed to teach counselors and problem gamblers about how electronic gambling machines (EGMs) work. This study evaluated the tutorial using assessment tools, such as rating scales and test of knowledge about EGMs and random chance. The study results are based on a number of samples, including problem gambling counselors ( n  = 25) and problem gamblers ( n  = 26). The interactive tutorial was positively rated by both clients and counselors. In addition, we found a significant improvement in scores on a content test about EGM games for both clients and counselors. An analysis of the specific items suggests that the effects of the tutorial were mainly on those items that were most directly related to the content of the tutorial and did not always generalize to other items. This tutorial is available for use with clients and for education counselors. The data also suggest that the tutorial is equally effective in group settings and in individual settings. These results are promising and illustrate that the tool can be used to teach counselors and clients about game design. Furthermore, research is needed to evaluate its impact on gambling behavior.

  13. Conceptual design of a synchronous Mars telecommunications satellite

    Science.gov (United States)

    Badi, Deborah M.; Farmer, Jeffrey T.; Garn, Paul A.; Martin, Gary L.

    1989-01-01

    Future missions to Mars will require a communications system to link activities on the Martian surface with each other and with mission controllers on Earth. A conceptual design is presented for an aerosynchronous communications satellite to provide these links. The satellite provides the capability for voice, data/command, and video transmissions. The mission scenario assumed for the design is described, and a description of a single aerosynchronous satellite is explained. A viable spacecraft design is then presented. Communication band selection and channel allocation are discussed. The communications system conceptual design is presented along with the trades used in sizing each of the required antennas. Also, the analyses used to develop the supporting subsystem designs are described as is the communications impact on each subsystem design.

  14. Time synchronization for an Ethernet-based real-time token network

    NARCIS (Netherlands)

    Hanssen, F.T.Y.; van den Boom, Joost; Jansen, P.G.; Scholten, Johan

    We present a distributed clock synchronization algorithm. It performs clock synchronization on an Ethernet-based real-time token local area network, without the use of an external clock source. It is used to enable the token schedulers in each node to agree upon a common time. Its intended use is in

  15. Space base laser torque applied on LEO satellites of various geometries at satellite’s closest approach

    Directory of Open Access Journals (Sweden)

    N.S. Khalifa

    2013-12-01

    Full Text Available In light of using laser power in space applications, the motivation of this paper is to use a space based solar pumped laser to produce a torque on LEO satellites of various shapes. It is assumed that there is a space station that fires laser beam toward the satellite so the beam spreading due to diffraction is considered to be the dominant effect on the laser beam propagation. The laser torque is calculated at the point of closest approach between the space station and some sun synchronous low Earth orbit cubesats. The numerical application shows that space based laser torque has a significant contribution on the LEO cubesats. It has a maximum value in the order of 10−8 Nm which is comparable with the residual magnetic moment. However, it has a minimum value in the order 10−11 Nm which is comparable with the aerodynamic and gravity gradient torque. Consequently, space based laser torque can be used as an active attitude control system.

  16. Tutorial on beam current monitoring

    International Nuclear Information System (INIS)

    Webber, Robert C.

    2000-01-01

    This paper is a tutorial level review covering a wide range of aspects related to charged particle beam current measurement. The tutorial begins with a look at the characteristics of the beam as a signal source, the associated electromagnetic fields, the influence of the typical accelerator environment on those fields, and the usual means of modifying and controlling that environment to facilitate beam current measurement. Short descriptions of three quite different types of current monitors are presented and a quantitative review of the classical transformer circuit is given. Recognizing that environmental noise pick-up may present a large source of error in quantitative measurements, signal handling considerations are given considerable attention using real-life examples. An example of a successful transport line beam current monitor implementation is presented and the tutorial concludes with a few comments about signal processing and current monitor calibration issues

  17. Synchronization of delay-coupled nonlinear oscillators: an approach based on the stability analysis of synchronized equilibria.

    Science.gov (United States)

    Michiels, Wim; Nijmeijer, Henk

    2009-09-01

    We consider the synchronization problem of an arbitrary number of coupled nonlinear oscillators with delays in the interconnections. The network topology is described by a directed graph. Unlike the conventional approach of deriving directly sufficient synchronization conditions, the approach of the paper starts from an exact stability analysis in a (gain, delay) parameter space of a synchronized equilibrium and extracts insights from an analysis of its bifurcations and from the corresponding emerging behavior. Instrumental to this analysis a factorization of the characteristic equation is employed that not only facilitates the analysis and reduces computational cost but also allows to determine the precise role of the individual agents and the topology of the network in the (in)stability mechanisms. The study provides an algorithm to perform a stability and bifurcation analysis of synchronized equilibria. Furthermore, it reveals fundamental limitations to synchronization and it explains under which conditions on the topology of the network and on the characteristics of the coupling the systems are expected to synchronize. In the second part of the paper the results are applied to coupled Lorenz systems. The main results show that for sufficiently large coupling gains, delay-coupled Lorenz systems exhibit a generic behavior that does not depend on the number of systems and the topology of the network, as long as some basic assumptions are satisfied, including the strong connectivity of the graph. Here the linearized stability analysis is strengthened by a nonlinear stability analysis which confirms the predictions based on the linearized stability and bifurcation analysis. This illustrates the usefulness of the exact linearized analysis in a situation where a direct nonlinear stability analysis is not possible or where it yields conservative conditions from which it is hard to get qualitative insights in the synchronization mechanisms and their scaling properties

  18. Adaptive Synchronization of Memristor-based Chaotic Neural Systems

    Directory of Open Access Journals (Sweden)

    Xiaofang Hu

    2014-11-01

    Full Text Available Chaotic neural networks consisting of a great number of chaotic neurons are able to reproduce the rich dynamics observed in biological nervous systems. In recent years, the memristor has attracted much interest in the efficient implementation of artificial synapses and neurons. This work addresses adaptive synchronization of a class of memristor-based neural chaotic systems using a novel adaptive backstepping approach. A systematic design procedure is presented. Simulation results have demonstrated the effectiveness of the proposed adaptive synchronization method and its potential in practical application of memristive chaotic oscillators in secure communication.

  19. A combined video and synchronous VSAT data network

    Science.gov (United States)

    Rowse, William

    Private Satellite Network currently operates Business Television networks for Fortune 500 companies. Several of these satellite-based networks, using VSAT technology, are combining the transmission of video with the broadcast of one-way data. This is made possible by use of the PSN Business Television Terminal which incorporates Scientific Atlanta's B-MAC system. In addition to providing high quality video, B-MAC can provide six channels of 204.5 kbs audio. Four of the six channels may be used to directly carry up to 19.2 kbs of asynchronous data or up to 56 kbs of synchronous data using circuitry jointly developed by PSN and Scientific Atlanta. The approach PSN has taken to provide one network customer in the financial industry with both video and broadcast data is described herein.

  20. Powder metallurgy ferrous synchronizer ring with brass-based friction layer; Tetsu-do niso shoketsu synchronize ring no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Okajima, H; Yoshikawa, K; Miyajima, K; Sugiyama, M [Toyota Motor Corp., Aichi (Japan); Nakamura, M; Ito, M [Japan Powder Metallurgy Co. Ltd., Tokyo (Japan)

    1997-10-01

    Synchronizer rings for manual transmissions are generally made of brass or molybdenum coated brass. Powder metallurgy (PM) synchronizer ring was developed for the purpose of high performance and cost reduction. This synchronizer ring consists of the high strength PM ferrous ring that needs neither special densification nor heat treatment, and it has the brass-based friction layer. New joining technique was required because of that shape and two different materials. Powder of copper-phosphorus alloy are admixed with the friction material. While sintering, that melt and migrate to the interface. Then the friction layer and the ferrous ring are joined tightly. 7 refs., 9 figs., 6 tabs.

  1. Effectiveness of a computer-based tutorial for teaching how to make a blood smear.

    Science.gov (United States)

    Preast, Vanessa; Danielson, Jared; Bender, Holly; Bousson, Maury

    2007-09-01

    Computer-aided instruction (CAI) was developed to teach veterinary students how to make blood smears. This instruction was intended to replace the traditional instructional method in order to promote efficient use of faculty resources while maintaining learning outcomes and student satisfaction. The purpose of this study was to evaluate the effect of a computer-aided blood smear tutorial on 1) instructor's teaching time, 2) students' ability to make blood smears, and 3) students' ability to recognize smear quality. Three laboratory sessions for senior veterinary students were taught using traditional methods (control group) and 4 sessions were taught using the CAI tutorial (experimental group). Students in the control group received a short demonstration and lecture by the instructor at the beginning of the laboratory and then practiced making blood smears. Students in the experimental group received their instruction through the self-paced, multimedia tutorial on a laptop computer and then practiced making blood smears. Data was collected from observation, interview, survey questionnaires, and smear evaluation by students and experts using a scoring rubric. Students using the CAI made better smears and were better able to recognize smear quality. The average time the instructor spent in the room was not significantly different between groups, but the quality of the instructor time was improved with the experimental instruction. The tutorial implementation effectively provided students and instructors with a teaching and learning experience superior to the traditional method of instruction. Using CAI is a viable method of teaching students to make blood smears.

  2. Advocacy and IPR, tutorial 4

    CERN Multimedia

    CERN. Geneva

    2005-01-01

    With open access and repositories assuming a high profile some may question whether advocacy is still necessary. Those involved in the business of setting up and populating repositories are aware that in the majority of institutions there is still a great need for advocacy. This tutorial will give participants an opportunity to discuss different advocacy methods and approaches, including the 'top down' and 'bottom up' approach, publicity methods and the opportunities offered by funding body positions on open access. Participants will have the opportunity to share experiences of what works and what doesn't. The advocacy role often encompasses responsibility for advising academics on IPR issues. This is a particularly critical area where repository staff are engaged in depositing content on behalf of academics. The tutorial will offer an opportunity to discuss the IPR issues encountered by those managing repositories. The tutorial will draw on the experience of participants who have been engaged in advocacy act...

  3. Implementation of the laser-based femtosecond precision synchronization system at FLASH

    International Nuclear Information System (INIS)

    Schulz, Sebastian

    2011-05-01

    FLASH, the high-gain free-electron laser (FEL) in Hamburg, enables the generation of light pulses with wavelengths in the soft X-ray region and durations down to a few femtoseconds. To fully exploit this capability in time-resolved pump-probe experiments, and for the projected externally seeded operation, the critical components of the accelerator and several external laser systems have to be synchronized with a temporal accuracy at least in the same order of magnitude. This can not be realized purely with established RF-based systems and therefore, an optical, laser-based synchronization system is required. In this thesis, the optical synchronization system of FLASH has been, based on previous successful proof-of-principle experiments, massively extended. One major topic is the comprehensive characterization of the timing reference of the system and a comparison of different types of such master laser oscillators, as well as studies on their short- and long-term stability. Similar investigations have been carried out for the upgraded and newly installed length-stabilized fiber links, which connect the remote locations at the accelerator to the optical timing reference. The successful demonstration of an all-optical synchronization of a Ti:sapphire oscillator with sub-10 femtosecond timing jitter and the connection of the photo injector laser system to the synchronization system mark further important key experiments of this thesis. The robustness of the actual implementations played a key role, as the synchronization system forms the basis for the future, operator-friendly arrival time feedback.

  4. Synchronization approach for chaotic time-varying delay system based on Wirtinger inequality

    Directory of Open Access Journals (Sweden)

    Zhanshan Zhao

    2017-01-01

    Full Text Available A novel control approach based on Wirtinger inequality is designed for nonlinear chaos synchronization time delay system. In order to reduce the conservatism for the stability criterion, a Lyapunov–Krasovskii functional with triple-integral term is constructed. The improved Wirtinger inequality is used to reduce the conservative which is caused by Jensen inequality, and a stability criterion is proposed by reciprocally convex method. Furthermore, a state feedback controller is designed to synchronize the master-slave systems based on the proposed criteria through cone complementary linearization approach. Finally, a simulation for Lorenz chaos time delay system is given to prove the validity based on the proposed synchronization control approach.

  5. CMAC-based adaptive backstepping synchronization of uncertain chaotic systems

    International Nuclear Information System (INIS)

    Lin, C.-M.; Peng, Y.-F.; Lin, M.-H.

    2009-01-01

    This study proposes an adaptive backstepping control system for synchronizing uncertain chaotic system by using cerebellar model articulation controller (CMAC). CMAC is a nonlinear network with simple computation, good generalization capability and fast learning property. The proposed CMAC-based adaptive backstepping control (CABC) system uses backstepping method and adaptive cerebellar model articulation controller (ACMAC) for synchronizing uncertain chaotic system. Finally, simulation results for the Genesio system are presented to illustrate the effectiveness of the proposed control system.

  6. Chaos synchronization based on intermittent state observer

    Institute of Scientific and Technical Information of China (English)

    Li Guo-Hui; Zhou Shi-Ping; Xu De-Ming

    2004-01-01

    This paper describes the method of synchronizing slave to the master trajectory using an intermittent state observer by constructing a synchronizer which drives the response system globally tracing the driving system asymptotically. It has been shown from the theory of synchronization error-analysis that a satisfactory result of chaos synchronization is expected under an appropriate intermittent period and state observer. Compared with continuous control method,the proposed intermittent method can target the desired orbit more efficiently. The application of the method is demonstrated on the hyperchaotic Rossler systems. Numerical simulations show that the length of the synchronization interval rs is of crucial importance for our scheme, and the method is robust with respect to parameter mismatch.

  7. The Purpose of Tutorial Groups: Social Influence and the Group as Means and Objective

    Science.gov (United States)

    Rosander, Michael; Chiriac, Eva Hammar

    2016-01-01

    The aim of this study was to investigate how first-year students view the purpose of tutorial groups in problem-based learning. In all, 147 students from 24 groups participated, providing 399 statements. Data were analysed using thematic analysis. The results showed a focus on both learning and social influence. Learning involved the tutorial as…

  8. Survival modeling for the estimation of transition probabilities in model-based economic evaluations in the absence of individual patient data: a tutorial.

    Science.gov (United States)

    Diaby, Vakaramoko; Adunlin, Georges; Montero, Alberto J

    2014-02-01

    Survival modeling techniques are increasingly being used as part of decision modeling for health economic evaluations. As many models are available, it is imperative for interested readers to know about the steps in selecting and using the most suitable ones. The objective of this paper is to propose a tutorial for the application of appropriate survival modeling techniques to estimate transition probabilities, for use in model-based economic evaluations, in the absence of individual patient data (IPD). An illustration of the use of the tutorial is provided based on the final progression-free survival (PFS) analysis of the BOLERO-2 trial in metastatic breast cancer (mBC). An algorithm was adopted from Guyot and colleagues, and was then run in the statistical package R to reconstruct IPD, based on the final PFS analysis of the BOLERO-2 trial. It should be emphasized that the reconstructed IPD represent an approximation of the original data. Afterwards, we fitted parametric models to the reconstructed IPD in the statistical package Stata. Both statistical and graphical tests were conducted to verify the relative and absolute validity of the findings. Finally, the equations for transition probabilities were derived using the general equation for transition probabilities used in model-based economic evaluations, and the parameters were estimated from fitted distributions. The results of the application of the tutorial suggest that the log-logistic model best fits the reconstructed data from the latest published Kaplan-Meier (KM) curves of the BOLERO-2 trial. Results from the regression analyses were confirmed graphically. An equation for transition probabilities was obtained for each arm of the BOLERO-2 trial. In this paper, a tutorial was proposed and used to estimate the transition probabilities for model-based economic evaluation, based on the results of the final PFS analysis of the BOLERO-2 trial in mBC. The results of our study can serve as a basis for any model

  9. Synchronization of uncertain time-varying network based on sliding mode control technique

    Science.gov (United States)

    Lü, Ling; Li, Chengren; Bai, Suyuan; Li, Gang; Rong, Tingting; Gao, Yan; Yan, Zhe

    2017-09-01

    We research synchronization of uncertain time-varying network based on sliding mode control technique. The sliding mode control technique is first modified so that it can be applied to network synchronization. Further, by choosing the appropriate sliding surface, the identification law of uncertain parameter, the adaptive law of the time-varying coupling matrix element and the control input of network are designed, it is sure that the uncertain time-varying network can synchronize effectively the synchronization target. At last, we perform some numerical simulations to demonstrate the effectiveness of the proposed results.

  10. The genre tutorial and social networks terminology

    Directory of Open Access Journals (Sweden)

    Márcio Sales Santiago

    2014-02-01

    Full Text Available This paper analyzes the terminology in the Internet social networks tutorials. A tutorial is a specialized text, full of terms, aiming to teach an individual or group of individuals who need some guidelines to operationalize a computerized tool, such as a social network. It is necessary to identify linguistic and terminological characteristics from the specialized lexical units in this digital genre. Social networks terminology is described and exemplified here. The results show that it is possible to refer to two specific terminologies in tutorials which help to determine the terminological profile of the thematic area, specifically from the point of view of denomination.

  11. Development and Evaluation of Internet-Based Hypermedia Chemistry Tutorials

    Science.gov (United States)

    Tissue, Brian M.; Earp, Ronald L.; Yip, Ching-Wan; Anderson, Mark R.

    1996-05-01

    This progress report describes the development and student use of World-Wide-Web-based prelaboratory exercises in senior-level Instrumental Analysis during the 1995 Fall semester. The laboratory preparation exercises contained hypermedia tutorials and multiple-choice questions that were intended to familiarize the students with the experiments and instrumentation before their laboratory session. The overall goal of our work is to explore ways in which computer and network technology can be applied in education to improve the cost-effectiveness and efficacy of teaching. The course material can be accessed at http://www.chem.vt.edu/chem-ed/4114/Fall1995.html. The students were instructed to read their experimental procedure and to do the relevant laboratory preparation exercise. The individual tutorial documents were primarily text that provided basic theoretical and experimental descriptions of analytical and instrumental methods. The documents included hyperlinks to basic concepts, simple schematics, and color graphics of experimental set-ups or instrumentation. We chose the World-Wide Web (WWW) as the delivery platform for this project because of the ease of developing, distributing, and modifying hypermedia material in a client-server system. The disadvantage of the WWW is that network bandwidth limits the size and sophistication of the hypermedia material. To minimize internet transfer time, the individual documents were kept short and usually contained no more than 3 or 4 inline images. After reading the tutorial the students answered several multiple-choice questions. The figure shows one example of a multiple-choice question and the response page. Clicking on the "Submit answer" button calls a *.cgi file, which contains instructions in the PERL interpretive language, that generates the response page and saves the date, time, and student's answer to a file on the server. Usage and student perception of the on-line material was evaluated from server logs and

  12. Finite time synchronization of memristor-based Cohen-Grossberg neural networks with mixed delays

    OpenAIRE

    Chen, Chuan; Li, Lixiang; Peng, Haipeng; Yang, Yixian

    2017-01-01

    Finite time synchronization, which means synchronization can be achieved in a settling time, is desirable in some practical applications. However, most of the published results on finite time synchronization don't include delays or only include discrete delays. In view of the fact that distributed delays inevitably exist in neural networks, this paper aims to investigate the finite time synchronization of memristor-based Cohen-Grossberg neural networks (MCGNNs) with both discrete delay and di...

  13. Asymptotic Behavior of an Elastic Satellite with Internal Friction

    International Nuclear Information System (INIS)

    Haus, E.; Bambusi, D.

    2015-01-01

    We study the dynamics of an elastic body whose shape and position evolve due to the gravitational forces exerted by a pointlike planet. The main result is that, if all the deformations of the satellite dissipate some energy, then under a suitable nondegeneracy condition there are only three possible outcomes for the dynamics: (i) the orbit of the satellite is unbounded, (ii) the satellite falls on the planet, (iii) the satellite is captured in synchronous resonance i.e. its orbit is asymptotic to a motion in which the barycenter moves on a circular orbit, and the satellite moves rigidly, always showing the same face to the planet. The result is obtained by making use of LaSalle’s invariance principle and by a careful kinematic analysis showing that energy stops dissipating only on synchronous orbits. We also use in quite an extensive way the fact that conservative elastodynamics is a Hamiltonian system invariant under the action of the rotation group

  14. Writing learning cases for an information literacy tutorial

    OpenAIRE

    Gunhild Austrheim

    2010-01-01

    The research and writing processes are often hidden mysteries to our students. A key point in the online tutorial Search and Write (Søk and Skriv) has been to supply our students with tools to handle these processes. Learning cases embedded in the tutorial allow us to demonstrate a variety of working techniques and to better cater for a diverse student population. The tutorial can be used as an independent resource for students and as a teaching aid for both library sessions on inform...

  15. Simulating climate with a synchronization-based supermodel

    Science.gov (United States)

    Selten, Frank M.; Schevenhoven, Francine J.; Duane, Gregory S.

    2017-12-01

    The SPEEDO global climate model (an atmosphere model coupled to a land and an ocean/sea-ice model with about 250.000 degrees of freedom) is used to investigate the merits of a new multi-model ensemble approach to the climate prediction problem in a perfect model setting. Two imperfect models are generated by perturbing parameters. Connection terms are introduced that synchronize the two models on a common solution, referred to as the supermodel solution. A synchronization-based learning algorithm is applied to the supermodel through the introduction of an update rule for the connection coefficients. Connection coefficients cease updating when synchronization errors between the supermodel and solutions of the "true" equations vanish. These final connection coefficients define the supermodel. Different supermodel solutions, but with equivalent performance, are found depending on the initial values of the connection coefficients during learning. The supermodels have a climatology and a climate response to a CO2 increase in the atmosphere that is closer to the truth as compared to the imperfect models and the standard multi-model ensemble average, showing the potential of the supermodel approach to improve climate predictions.

  16. Chaotic map based key agreement with/out clock synchronization

    International Nuclear Information System (INIS)

    Han, S.; Chang, E.

    2009-01-01

    In order to address Bergamo et al.'s attack, Xiao et al. proposed a key agreement protocol using chaotic maps. Han then presented three attacks on Xiao et al.'s protocol. To enhance the security of key agreement based on chaotic maps, Chang et al. proposed a new key agreement using passphrase, which works in clock synchronization environment. However, their protocol still has some issues: one is its passphrase is not easy to remember and much longer than password; the second one is it cannot resist guessing attack if the constructed passphrase is easy to remember and also has already existed in some rational dictionaries; the third one is it cannot work without clock synchronization. In this paper, we will present two different key agreement protocols, which can resist guessing attack. The first one works in clock synchronization environment. The second one can work without clock synchronization. They both use authenticated password for secure communications. The protocols are secure against replaying attacks and a shared session key can be established.

  17. Tutorial Continuing Education: Innovative Strategy in a Tertiary Specialized Health Unit

    Directory of Open Access Journals (Sweden)

    Flaviana Maciel

    2017-06-01

    Full Text Available Hospital Pelopidas Silveira-IMIP/SES/SUS is a tertiary-unit, specialized in cardiology, neurology, neurosurgery and interventional radiology. It is the only hospital of Brazilian Public-Health-System (SUS with this profile and a 24h-acute-cardio/neurovascular facility. Challenges of Continuing-Education include a guaranteeing appropriate level of basic knowledge, b empowering clinical staff to remain up to date in current knowledge. HPS Continuing-Education Program is based on three branches: a Classroom-Tutorials (CT, b Online-Tutorials at "Pelopidas Digital" Virtual-Teaching-Platform (PD-VTP and c Daily-Practice Evaluation (DPE. This paper presents logistic details of HPS Continuing-Education Program. Training team coordinates tutorial meetings and performs continuous statistical analysis. Evaluation team visit hospital departments daily, observing in practice the incorporation of information provided, and retraining individuals in their work scenarios. Both teams perform curriculum development, meeting planning and creation of digital-training-modules. Tutorial meetings have pre/post-tests, allowing monitoring of attendance, topic significance and short-term retention. Tutorial groups are formed by 6-12 employees sharing similarities in training needs. CT is offered to 4 groups-of-interest: a nurses, b nursing assistants, c administrative staff, porters, drivers, d cleaning, laundry and security staff. Problematization and active strategies have resulted into an attractive, structured educational program customized to produce short-term results. The strategy is of interest to institutions sharing similar challenges.

  18. New type of chaos synchronization in discrete-time systems: the F-M synchronization

    Directory of Open Access Journals (Sweden)

    Ouannas Adel

    2018-04-01

    Full Text Available In this paper, a new type of synchronization for chaotic (hyperchaotic maps with different dimensions is proposed. The novel scheme is called F – M synchronization, since it combines the inverse generalized synchronization (based on a functional relationship F with the matrix projective synchronization (based on a matrix M. In particular, the proposed approach enables F – M synchronization with index d to be achieved between n-dimensional drive system map and m-dimensional response system map, where the synchronization index d corresponds to the dimension of the synchronization error. The technique, which exploits nonlinear controllers and Lyapunov stability theory, proves to be effective in achieving the F – M synchronization not only when the synchronization index d equals n or m, but even if the synchronization index d is larger than the map dimensions n and m. Finally, simulation results are reported, with the aim to illustrate the capabilities of the novel scheme proposed herein.

  19. New type of chaos synchronization in discrete-time systems: the F-M synchronization

    Science.gov (United States)

    Ouannas, Adel; Grassi, Giuseppe; Karouma, Abdulrahman; Ziar, Toufik; Wang, Xiong; Pham, Viet-Thanh

    2018-04-01

    In this paper, a new type of synchronization for chaotic (hyperchaotic) maps with different dimensions is proposed. The novel scheme is called F - M synchronization, since it combines the inverse generalized synchronization (based on a functional relationship F) with the matrix projective synchronization (based on a matrix M). In particular, the proposed approach enables F - M synchronization with index d to be achieved between n-dimensional drive system map and m-dimensional response system map, where the synchronization index d corresponds to the dimension of the synchronization error. The technique, which exploits nonlinear controllers and Lyapunov stability theory, proves to be effective in achieving the F - M synchronization not only when the synchronization index d equals n or m, but even if the synchronization index d is larger than the map dimensions n and m. Finally, simulation results are reported, with the aim to illustrate the capabilities of the novel scheme proposed herein.

  20. TUTORIAL COACHING AS A STRATEGY OF PROFESSIONAL AND PERSONAL DEVELOPMENT: AN EXPERIENCE-BASED STUDY IN A SECONDARY EDUCATION INSTITUTE

    Directory of Open Access Journals (Sweden)

    GLADYS IBETH ARIZA ORDÓÑEZ

    2005-01-01

    Full Text Available Tutorial accompaniment constitutes at present a necessary alternative in the framework of higher education. This workstarts with a general conceptualization of the tutorial, and makes a review of the styles, methods and proceduresrelated to this academic life facet which can effectively contribute to reach the goals the present higher education pursuitwhen it is applied in a coherent and systematic way.Considering the changes that the economy as well as the legislation have generated in education, and mainly in thoseLatin-American university programs, it is necessary to generate changing processes on the curriculum conceptualization,the teaching activities and the academic planning, and also to promote tutorial programs to the students, in order torespond to the difficulties they confront along the different stages of their lives. This research emerges from the onecarried out about the effectiveness of a tutorial program at a Psychology Department. It pretends to highlight theprincipal points of the accompaniment tutorial programs that require to be adjusted and adapted, in order to facilitatean educational service aimed to consider not only the professional training but the personal formation as well.

  1. The SIKS/BiGGrid Big Data Tutorial

    NARCIS (Netherlands)

    Hiemstra, Djoerd; Lammerts, Evert; de Vries, A.P.

    2011-01-01

    The School for Information and Knowledge Systems SIKS and the Dutch e-science grid BiG Grid organized a new two-day tutorial on Big Data at the University of Twente on 30 November and 1 December 2011, just preceding the Dutch-Belgian Database Day. The tutorial is on top of some exciting new

  2. Audio-Tutorial Instruction: A Strategy For Teaching Introductory College Geology.

    Science.gov (United States)

    Fenner, Peter; Andrews, Ted F.

    The rationale of audio-tutorial instruction is discussed, and the history and development of the audio-tutorial botany program at Purdue University is described. Audio-tutorial programs in geology at eleven colleges and one school are described, illustrating several ways in which programs have been developed and integrated into courses. Programs…

  3. Web-based computational chemistry education with CHARMMing I: Lessons and tutorial.

    Science.gov (United States)

    Miller, Benjamin T; Singh, Rishi P; Schalk, Vinushka; Pevzner, Yuri; Sun, Jingjun; Miller, Carrie S; Boresch, Stefan; Ichiye, Toshiko; Brooks, Bernard R; Woodcock, H Lee

    2014-07-01

    This article describes the development, implementation, and use of web-based "lessons" to introduce students and other newcomers to computer simulations of biological macromolecules. These lessons, i.e., interactive step-by-step instructions for performing common molecular simulation tasks, are integrated into the collaboratively developed CHARMM INterface and Graphics (CHARMMing) web user interface (http://www.charmming.org). Several lessons have already been developed with new ones easily added via a provided Python script. In addition to CHARMMing's new lessons functionality, web-based graphical capabilities have been overhauled and are fully compatible with modern mobile web browsers (e.g., phones and tablets), allowing easy integration of these advanced simulation techniques into coursework. Finally, one of the primary objections to web-based systems like CHARMMing has been that "point and click" simulation set-up does little to teach the user about the underlying physics, biology, and computational methods being applied. In response to this criticism, we have developed a freely available tutorial to bridge the gap between graphical simulation setup and the technical knowledge necessary to perform simulations without user interface assistance.

  4. Web-based computational chemistry education with CHARMMing I: Lessons and tutorial.

    Directory of Open Access Journals (Sweden)

    Benjamin T Miller

    2014-07-01

    Full Text Available This article describes the development, implementation, and use of web-based "lessons" to introduce students and other newcomers to computer simulations of biological macromolecules. These lessons, i.e., interactive step-by-step instructions for performing common molecular simulation tasks, are integrated into the collaboratively developed CHARMM INterface and Graphics (CHARMMing web user interface (http://www.charmming.org. Several lessons have already been developed with new ones easily added via a provided Python script. In addition to CHARMMing's new lessons functionality, web-based graphical capabilities have been overhauled and are fully compatible with modern mobile web browsers (e.g., phones and tablets, allowing easy integration of these advanced simulation techniques into coursework. Finally, one of the primary objections to web-based systems like CHARMMing has been that "point and click" simulation set-up does little to teach the user about the underlying physics, biology, and computational methods being applied. In response to this criticism, we have developed a freely available tutorial to bridge the gap between graphical simulation setup and the technical knowledge necessary to perform simulations without user interface assistance.

  5. Adaptive observer based synchronization of a class of uncertain chaotic systems

    International Nuclear Information System (INIS)

    Bowong, S.; Yamapi, R.

    2005-05-01

    This study addresses the adaptive synchronization of a class of uncertain chaotic systems in the drive-response framework. For a class of uncertain chaotic systems with unknown parameters and external disturbances, a robust adaptive observer based response system is constructed to synchronize the uncertain chaotic system. Lyapunov stability theory and Barbalat lemma ensure the global synchronization between the drive and response systems even if Lipschitz constants on function matrices and bounds on uncertainties are unknown. Numerical simulation of the Genesio-Tesi system verifies the effectiveness of the proposed method. (author)

  6. Captivate MenuBuilder: Creating an Online Tutorial for Teaching Software

    Science.gov (United States)

    Yelinek, Kathryn; Tarnowski, Lynn; Hannon, Patricia; Oliver, Susan

    2008-01-01

    In this article, the authors, students in an instructional technology graduate course, describe a process to create an online tutorial for teaching software. They created the tutorial for a cyber school's use. Five tutorial modules were linked together through one menu screen using the MenuBuilder feature in the Adobe Captivate program. The…

  7. Comparing the Effectiveness of a Supplemental Online Tutorial to Traditional Instruction with Nutritional Science Students

    Science.gov (United States)

    Zubas, Patrice; Heiss, Cindy; Pedersen, Mary

    2006-01-01

    The purpose of this study was to ascertain if an online computer tutorial on diabetes mellitus, supplemented to traditional classroom lecture, is an effective tool in the education of nutrition students. Students completing a web-based tutorial as a supplement to classroom lecture displayed greater improvement in pre- vs. post-test scores compared…

  8. Clock synchronisation experiment in India using symphonie satellite

    Science.gov (United States)

    Somayajulu, Y. V.; Mathur, B. S.; Banerjee, P.; Garg, S. C.; Singh, L.; Sood, P. C.; Tyagi, T. R.; Jain, C. L.; Kumar, K.

    1979-01-01

    A recent clock synchronization experiment between the National Physical Laboratory (NPL), New Delhi and Space Applications Center (SAC), Ahemedabad, in India via geostationary satellite symphonie 2, stationed at 49 E longitude, is reported. A two-way transmission using a microwave transponder considered to provide the greatest precision in synchronization of two remote clocks is described.

  9. Multi-camera synchronization core implemented on USB3 based FPGA platform

    Science.gov (United States)

    Sousa, Ricardo M.; Wäny, Martin; Santos, Pedro; Dias, Morgado

    2015-03-01

    Centered on Awaiba's NanEye CMOS image sensor family and a FPGA platform with USB3 interface, the aim of this paper is to demonstrate a new technique to synchronize up to 8 individual self-timed cameras with minimal error. Small form factor self-timed camera modules of 1 mm x 1 mm or smaller do not normally allow external synchronization. However, for stereo vision or 3D reconstruction with multiple cameras as well as for applications requiring pulsed illumination it is required to synchronize multiple cameras. In this work, the challenge of synchronizing multiple selftimed cameras with only 4 wire interface has been solved by adaptively regulating the power supply for each of the cameras. To that effect, a control core was created to constantly monitor the operating frequency of each camera by measuring the line period in each frame based on a well-defined sampling signal. The frequency is adjusted by varying the voltage level applied to the sensor based on the error between the measured line period and the desired line period. To ensure phase synchronization between frames, a Master-Slave interface was implemented. A single camera is defined as the Master, with its operating frequency being controlled directly through a PC based interface. The remaining cameras are setup in Slave mode and are interfaced directly with the Master camera control module. This enables the remaining cameras to monitor its line and frame period and adjust their own to achieve phase and frequency synchronization. The result of this work will allow the implementation of smaller than 3mm diameter 3D stereo vision equipment in medical endoscopic context, such as endoscopic surgical robotic or micro invasive surgery.

  10. Theory of geostationary satellites

    CERN Document Server

    Zee, Chong-Hung

    1989-01-01

    Geostationary or equatorial synchronous satellites are a daily reminder of our space efforts during the past two decades. The nightly television satellite weather picture, the intercontinental telecommunications of television transmissions and telephone conversations, and the establishrnent of educational programs in remote regions on Earth are constant reminders of the presence of these satellites. As used here, the term 'geo­ stationary' must be taken loosely because, in the long run, the satellites will not remain 'stationary' with respect to an Earth-fixed reference frame. This results from the fact that these satellites, as is true for all satellites, are incessantly subject to perturbations other than the central-body attraction of the Earth. Among the more predominant pertur­ bations are: the ellipticity of the Earth's equator, the Sun and Moon, and solar radiation pressure. Higher harmonics of the Earth's potential and tidal effects also influence satellite motion, but they are of second­ order whe...

  11. Caregiver's satisfaction with a video tutorial for shoulder dystocia management algorithm.

    Science.gov (United States)

    Youssef, A; Salsi, G; Ragusa, A; Ghi, T; Pacella, G; Rizzo, N; Pilu, G

    2015-01-01

    In our questionnaire, a video tutorial illustrating the management of shoulder dystocia was considered by health personnel as a useful complementary training tool. We prepared a 5-min video tutorial on the management of shoulder dystocia, using a simulator that includes maternal pelvic and baby models. We performed a survey among obstetric personnel in order to assess their opinion on the tutorial by inviting them to watch the video tutorial and answer an online questionnaire. Five multiple-choice questions were set, focusing on the video's main objectives: clarity, simplicity and usefulness. Following the collection of answers, global and category-weighted analyses were conducted for each question. Out of 956 invitations sent, 482 (50.4%) answered the survey. More than 90% of all categories found the video tutorial to be clinically relevant and clear. For revising the management of shoulder dystocia most obstetric personnel would use the video tutorial together with traditional textbooks. In conclusion, our video tutorial was considered by health personnel as a useful complementary training tool.

  12. Mail2Print online tutorial

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Mail2print is a feature which allows you to send documents to a printer by mail. This tutorial (text attached to the event page) explains how to use this service. Content owner: Vincent Nicolas Bippus Presenter: Pedro Augusto de Freitas Batista Tell us what you think via e-learning.support at cern.ch More tutorials in the e-learning collection of the CERN Document Server (CDS) https://cds.cern.ch/collection/E-learning%20modules?ln=en All info about the CERN rapid e-learning project is linked from http://twiki.cern.ch/ELearning  

  13. ACTS TDMA network control. [Advanced Communication Technology Satellite

    Science.gov (United States)

    Inukai, T.; Campanella, S. J.

    1984-01-01

    This paper presents basic network control concepts for the Advanced Communications Technology Satellite (ACTS) System. Two experimental systems, called the low-burst-rate and high-burst-rate systems, along with ACTS ground system features, are described. The network control issues addressed include frame structures, acquisition and synchronization procedures, coordinated station burst-time plan and satellite-time plan changes, on-board clock control based on ground drift measurements, rain fade control by means of adaptive forward-error-correction (FEC) coding and transmit power augmentation, and reassignment of channel capacities on demand. The NASA ground system, which includes a primary station, diversity station, and master control station, is also described.

  14. SFO-Project: The New Generation of Sharable, Editable and Open-Access CFD Tutorials

    Science.gov (United States)

    Javaherchi, Teymour; Javaherchi, Ardeshir; Aliseda, Alberto

    2016-11-01

    One of the most common approaches to develop a Computational Fluid Dynamic (CFD) simulation for a new case study of interest is to search for the most similar, previously developed and validated CFD simulation among other works. A simple search would result into a pool of written/visual tutorials. However, users should spend significant amount of time and effort to find the most correct, compatible and valid tutorial in this pool and further modify it toward their simulation of interest. SFO is an open-source project with the core idea of saving the above-mentioned time and effort. This is done via documenting/sharing scientific and methodological approaches to develop CFD simulations for a wide spectrum of fundamental and industrial case studies in three different CFD solvers; STAR-CCM +, FLUENT and Open FOAM (SFO). All of the steps and required files of these tutorials are accessible and editable under the common roof of Github (a web-based Git repository hosting service). In this presentation we will present the current library of 20 + developed CFD tutorials, discuss the idea and benefit of using them, their educational values and explain how the next generation of open-access and live resource of CFD tutorials can be built further hand-in-hand within our community.

  15. Intelligent tutorial system for selftraining in tuning of control systems; Sistema tutorial inteligente para el autoentrenamiento en sintonizacion de sistemas de control

    Energy Technology Data Exchange (ETDEWEB)

    Romero Jimenez, Guillermo; Perez Ocampo, Maria Concepcion [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    1999-07-01

    In this paper the design, development and validation of an intelligent tutorial system oriented to the instruction of techniques of tuning of control systems is described. This system is based on systems previously developed in the Simulation Unit of the Instituto de Investigaciones Electricas (IIE). The designed system accounts with four modules: of knowledge, the student model, of tutor and of interface, basic characteristics that allows to locate this system in the context of the intelligent tutorial systems. In this system in particular, the knowledge module was only modified, because advantage is taken of the existing structure to incorporate a new dominion of application: the one of the techniques of tuning of control systems. The system maintains the characteristic that it can also be used as a consultation system. In addition to the design and validation of the tutorial system, when following the methodology of processing the degree of generality of the developed system, was evaluated, taking into account the evaluation and quantification of metrics that the engineering software proposes. [Spanish] En este trabajo se describen el diseno, el desarrollo y la validacion de un sistema tutorial inteligente orientado a la instruccion de tecnicas de sintonizacion de sistemas de control. Este sistema esta basado en sistemas desarrollados anteriormente en la Unidad de Simulacion del Instituto de Investigaciones Electricas (IIE). El sistema disenado cuenta con cuatro modulos: de conocimiento, del modelo del estudiante, de tutor y de interfaz, caracteristica principal que permite ubicar a este sistema en el contexto de los sistemas tutoriales inteligentes. En este sistema en particular solo se modifica el modulo de conocimiento, pues se aprovecha la estructura existente para incorporar un nuevo dominio de aplicacion: el de las tecnicas de sintonizacion de sistemas de control. El sistema mantiene la caracteristica de que tambien puede utilizarse como un sistema de

  16. Synchronous Generator Model Parameter Estimation Based on Noisy Dynamic Waveforms

    Science.gov (United States)

    Berhausen, Sebastian; Paszek, Stefan

    2016-01-01

    In recent years, there have occurred system failures in many power systems all over the world. They have resulted in a lack of power supply to a large number of recipients. To minimize the risk of occurrence of power failures, it is necessary to perform multivariate investigations, including simulations, of power system operating conditions. To conduct reliable simulations, the current base of parameters of the models of generating units, containing the models of synchronous generators, is necessary. In the paper, there is presented a method for parameter estimation of a synchronous generator nonlinear model based on the analysis of selected transient waveforms caused by introducing a disturbance (in the form of a pseudorandom signal) in the generator voltage regulation channel. The parameter estimation was performed by minimizing the objective function defined as a mean square error for deviations between the measurement waveforms and the waveforms calculated based on the generator mathematical model. A hybrid algorithm was used for the minimization of the objective function. In the paper, there is described a filter system used for filtering the noisy measurement waveforms. The calculation results of the model of a 44 kW synchronous generator installed on a laboratory stand of the Institute of Electrical Engineering and Computer Science of the Silesian University of Technology are also given. The presented estimation method can be successfully applied to parameter estimation of different models of high-power synchronous generators operating in a power system.

  17. Tutorial de calcul poromécanique avec le logiciel Abaqus

    OpenAIRE

    Bonelli, S.

    2011-01-01

    / Ce tutorial est destiné à apprendre à réaliser avec Abaqus, sous CAE, un calcul de poroélasticité linéaire. Il est écrit de telle sorte que quelqu'un n'ayant jamais utilisé Abaqus, mais ayant des connaissances de base en mécanique des milieux poreux d'une part, et en éléments-finis d'autre part, puisse réaliser un tel calcul en partant de zéro. Toutefois, il ne s'agit en aucun cas d'un tutorial sur Abaqus ui-même, ni sur la méthode des éléments-finis.

  18. Finite time synchronization of memristor-based Cohen-Grossberg neural networks with mixed delays

    Science.gov (United States)

    2017-01-01

    Finite time synchronization, which means synchronization can be achieved in a settling time, is desirable in some practical applications. However, most of the published results on finite time synchronization don’t include delays or only include discrete delays. In view of the fact that distributed delays inevitably exist in neural networks, this paper aims to investigate the finite time synchronization of memristor-based Cohen-Grossberg neural networks (MCGNNs) with both discrete delay and distributed delay (mixed delays). By means of a simple feedback controller and novel finite time synchronization analysis methods, several new criteria are derived to ensure the finite time synchronization of MCGNNs with mixed delays. The obtained criteria are very concise and easy to verify. Numerical simulations are presented to demonstrate the effectiveness of our theoretical results. PMID:28931066

  19. Finite time synchronization of memristor-based Cohen-Grossberg neural networks with mixed delays.

    Science.gov (United States)

    Chen, Chuan; Li, Lixiang; Peng, Haipeng; Yang, Yixian

    2017-01-01

    Finite time synchronization, which means synchronization can be achieved in a settling time, is desirable in some practical applications. However, most of the published results on finite time synchronization don't include delays or only include discrete delays. In view of the fact that distributed delays inevitably exist in neural networks, this paper aims to investigate the finite time synchronization of memristor-based Cohen-Grossberg neural networks (MCGNNs) with both discrete delay and distributed delay (mixed delays). By means of a simple feedback controller and novel finite time synchronization analysis methods, several new criteria are derived to ensure the finite time synchronization of MCGNNs with mixed delays. The obtained criteria are very concise and easy to verify. Numerical simulations are presented to demonstrate the effectiveness of our theoretical results.

  20. Finite time synchronization of memristor-based Cohen-Grossberg neural networks with mixed delays.

    Directory of Open Access Journals (Sweden)

    Chuan Chen

    Full Text Available Finite time synchronization, which means synchronization can be achieved in a settling time, is desirable in some practical applications. However, most of the published results on finite time synchronization don't include delays or only include discrete delays. In view of the fact that distributed delays inevitably exist in neural networks, this paper aims to investigate the finite time synchronization of memristor-based Cohen-Grossberg neural networks (MCGNNs with both discrete delay and distributed delay (mixed delays. By means of a simple feedback controller and novel finite time synchronization analysis methods, several new criteria are derived to ensure the finite time synchronization of MCGNNs with mixed delays. The obtained criteria are very concise and easy to verify. Numerical simulations are presented to demonstrate the effectiveness of our theoretical results.

  1. Assimilation of contents and learning through the use of video tutorials

    Directory of Open Access Journals (Sweden)

    David JIMÉNEZ CASTILLO

    2013-01-01

    Full Text Available The need for a change in the university educational model promoted by the establishment of the European Higher Education Area (EHEA has promoted the implementation of numerous proposals for innovation in university teaching. These innovative practices that are based on a process of reflection and analysis of past teaching experience, are helping to improve qualitatively the teaching practice and, consequently, the learning process and outcomes of students, from a process of reflection and analysis of the teaching experience. In this context, this paper focuses on analyzing a specific teaching tool for innovation, the video tutorial, in order to assess its influence on the processes of assimilation of contents and self-learning. In particular, we attempt to show if the video tutorial allows reinforcing the understanding of practical contents that have been previously given by the classical method of masterly exposition. From the analysis of data obtained through a survey directed to a sample of students after experimenting with the teaching tool, it is shown that the video tutorial is considered a very suitable tool to improve the assimilation capacity of the contents taught previously and to acquire higher learning. After performing a regression analysis, the research also shows that students’ attitudes toward multimedia tools and the perceived utility of video tutorial positively influence these capacities. On the contrary, we find that the attitude towards individual learning and the attention paid by the student to the contents of the video tutorial do not affect the level of learning obtained from this tool.

  2. Fault Location Based on Synchronized Measurements: A Comprehensive Survey

    Science.gov (United States)

    Al-Mohammed, A. H.; Abido, M. A.

    2014-01-01

    This paper presents a comprehensive survey on transmission and distribution fault location algorithms that utilize synchronized measurements. Algorithms based on two-end synchronized measurements and fault location algorithms on three-terminal and multiterminal lines are reviewed. Series capacitors equipped with metal oxide varistors (MOVs), when set on a transmission line, create certain problems for line fault locators and, therefore, fault location on series-compensated lines is discussed. The paper reports the work carried out on adaptive fault location algorithms aiming at achieving better fault location accuracy. Work associated with fault location on power system networks, although limited, is also summarized. Additionally, the nonstandard high-frequency-related fault location techniques based on wavelet transform are discussed. Finally, the paper highlights the area for future research. PMID:24701191

  3. Fault Location Based on Synchronized Measurements: A Comprehensive Survey

    Directory of Open Access Journals (Sweden)

    A. H. Al-Mohammed

    2014-01-01

    Full Text Available This paper presents a comprehensive survey on transmission and distribution fault location algorithms that utilize synchronized measurements. Algorithms based on two-end synchronized measurements and fault location algorithms on three-terminal and multiterminal lines are reviewed. Series capacitors equipped with metal oxide varistors (MOVs, when set on a transmission line, create certain problems for line fault locators and, therefore, fault location on series-compensated lines is discussed. The paper reports the work carried out on adaptive fault location algorithms aiming at achieving better fault location accuracy. Work associated with fault location on power system networks, although limited, is also summarized. Additionally, the nonstandard high-frequency-related fault location techniques based on wavelet transform are discussed. Finally, the paper highlights the area for future research.

  4. Satellite-Based Precipitation Datasets

    Science.gov (United States)

    Munchak, S. J.; Huffman, G. J.

    2017-12-01

    Of the possible sources of precipitation data, those based on satellites provide the greatest spatial coverage. There is a wide selection of datasets, algorithms, and versions from which to choose, which can be confusing to non-specialists wishing to use the data. The International Precipitation Working Group (IPWG) maintains tables of the major publicly available, long-term, quasi-global precipitation data sets (http://www.isac.cnr.it/ ipwg/data/datasets.html), and this talk briefly reviews the various categories. As examples, NASA provides two sets of quasi-global precipitation data sets: the older Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) and current Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (GPM) mission (IMERG). Both provide near-real-time and post-real-time products that are uniformly gridded in space and time. The TMPA products are 3-hourly 0.25°x0.25° on the latitude band 50°N-S for about 16 years, while the IMERG products are half-hourly 0.1°x0.1° on 60°N-S for over 3 years (with plans to go to 16+ years in Spring 2018). In addition to the precipitation estimates, each data set provides fields of other variables, such as the satellite sensor providing estimates and estimated random error. The discussion concludes with advice about determining suitability for use, the necessity of being clear about product names and versions, and the need for continued support for satellite- and surface-based observation.

  5. Satellite-based laser windsounder

    International Nuclear Information System (INIS)

    Schultz, J.F.; Czuchlewski, S.J.; Quick, C.R.

    1997-01-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project''s primary objective is to determine the technical feasibility of using satellite-based laser wind sensing systems for detailed study of winds, aerosols, and particulates around and downstream of suspected proliferation facilities. Extensive interactions with the relevant operational organization resulted in enthusiastic support and useful guidance with respect to measurement requirements and priorities. Four candidate wind sensing techniques were evaluated, and the incoherent Doppler technique was selected. A small satellite concept design study was completed to identify the technical issues inherent in a proof-of-concept small satellite mission. Use of a Mach-Zehnder interferometer instead of a Fabry-Perot would significantly simplify the optical train and could reduce weight, and possibly power, requirements with no loss of performance. A breadboard Mach-Zehnder interferometer-based system has been built to verify these predictions. Detailed plans were made for resolving other issues through construction and testing of a ground-based lidar system in collaboration with the University of Wisconsin, and through numerical lidar wind data assimilation studies

  6. Machine Translation Using Constraint-Based Synchronous Grammar

    Institute of Scientific and Technical Information of China (English)

    WONG Fai; DONG Mingchui; HU Dongcheng

    2006-01-01

    A synchronous grammar based on the formalism of context-free grammar was developed by generalizing the first component of production that models the source text. Unlike other synchronous grammars,the grammar allows multiple target productions to be associated to a single production rule which can be used to guide a parser to infer different possible translational equivalences for a recognized input string according to the feature constraints of symbols in the pattern. An extended generalized LR algorithm was adapted to the parsing of the proposed formalism to analyze the syntactic structure of a language. The grammar was used as the basis for building a machine translation system for Portuguese to Chinese translation. The empirical results show that the grammar is more expressive when modeling the translational equivalences of parallel texts for machine translation and grammar rewriting applications.

  7. Dynamical systems on networks a tutorial

    CERN Document Server

    Porter, Mason A

    2016-01-01

    This volume is a tutorial for the study of dynamical systems on networks. It discusses both methodology and models, including spreading models for social and biological contagions. The authors focus especially on “simple” situations that are analytically tractable, because they are insightful and provide useful springboards for the study of more complicated scenarios. This tutorial, which also includes key pointers to the literature, should be helpful for junior and senior undergraduate students, graduate students, and researchers from mathematics, physics, and engineering who seek to study dynamical systems on networks but who may not have prior experience with graph theory or networks. Mason A. Porter is Professor of Nonlinear and Complex Systems at the Oxford Centre for Industrial and Applied Mathematics, Mathematical Institute, University of Oxford, UK. He is also a member of the CABDyN Complexity Centre and a Tutorial Fellow of Somerville College. James P. Gleeson is Professor of Industrial and Appli...

  8. Web-tutorials in context

    DEFF Research Database (Denmark)

    Lund, Haakon; Pors, Niels Ole

    2012-01-01

    Purpose – The purpose of the research is to investigate Norwegian web‐tutorials in contexts consisting of organizational issues and different forms of usability in relation to students’ perception and use of the system. Further, the research investigates the usefulness of the concepts concerning...... affordances and different forms of usability. Design/methodology/approach – The research has employed a variety of data‐collection methods including interviews with librarians, interviews and focus group interviews with students, coupled with tests of their capabilities using the systems. A detailed research...... the tutorials as part of the requirements. Further, examples of organizational amnesia are discussed, pointing to the necessity for leadership support and systematic knowledge sharing. System Usability Scores are analysed in relation to solution of tasks and interesting relations are analysed. The perceptions...

  9. Oracle support provides a range of new tutorials

    CERN Multimedia

    2012-01-01

    The IT DB is pleased to announce a new series of Oracle tutorials, with the proposed schedule. Note that these tutorials will take place in the Filtration Plant (Building 222) and that no registration is required.   4 June (Monday) 09:00 Oracle Architecture, Przemyslaw Adam Radowiecki The objective is to go through Oracle database physical and logical structures, highlighting the consequences of some of Oracle's internal design choices for developers of database applications. The presentation defines Oracle-related basic terms and illustrates them based on the database architecture. The following topics will be discussed: • Database with its physical and logical structures (tablespace, segment, extent, block, database user, schema, user's quota) • Single instance (significant memory structures: buffer cache, shared pool) • Real Application Cluster (RAC) • Connecting to the database (TNS, database service) • SQL statement processing (h...

  10. Iterative Decoding of Concatenated Codes: A Tutorial

    Directory of Open Access Journals (Sweden)

    Phillip A. Regalia

    2005-05-01

    Full Text Available The turbo decoding algorithm of a decade ago constituted a milestone in error-correction coding for digital communications, and has inspired extensions to generalized receiver topologies, including turbo equalization, turbo synchronization, and turbo CDMA, among others. Despite an accrued understanding of iterative decoding over the years, the “turbo principle” remains elusive to master analytically, thereby inciting interest from researchers outside the communications domain. In this spirit, we develop a tutorial presentation of iterative decoding for parallel and serial concatenated codes, in terms hopefully accessible to a broader audience. We motivate iterative decoding as a computationally tractable attempt to approach maximum-likelihood decoding, and characterize fixed points in terms of a “consensus” property between constituent decoders. We review how the decoding algorithm for both parallel and serial concatenated codes coincides with an alternating projection algorithm, which allows one to identify conditions under which the algorithm indeed converges to a maximum-likelihood solution, in terms of particular likelihood functions factoring into the product of their marginals. The presentation emphasizes a common framework applicable to both parallel and serial concatenated codes.

  11. How Levels of Interactivity in Tutorials Affect Students' Learning of Modeling Transportation Problems in a Spreadsheet

    Science.gov (United States)

    Seal, Kala Chand; Przasnyski, Zbigniew H.; Leon, Linda A.

    2010-01-01

    Do students learn to model OR/MS problems better by using computer-based interactive tutorials and, if so, does increased interactivity in the tutorials lead to better learning? In order to determine the effect of different levels of interactivity on student learning, we used screen capture technology to design interactive support materials for…

  12. Interdisciplinary, Application-Oriented Tutorials: Design, Implementation, and Evaluation

    Science.gov (United States)

    Herman, Carolyn; Casiday, Rachel E.; Deppe, Roberta K.; Gilbertson, Michelle; Spees, William M.; Holten, Dewey; Frey, Regina F.

    2005-01-01

    Fifteen application-oriented chemical tutorials were developed out of which thirteen are currently in use in the general chemistry lab rotary curriculum for chemistry students at Washington University from 1998 to 2000. The central philosophy of the tutorial that the students learn to combine information from variety of sources like science…

  13. Observer based on sliding mode variable structure for synchronization of chaotic systems

    International Nuclear Information System (INIS)

    Yin Xunhe; Shan Xiuming; Ren Yong

    2003-01-01

    In the paper an approach, based on the state observer of sliding mode variable structure, is used for synchronizing chaotic systems. It does not require either the computation of the Lyapunov exponents, or the initial conditions belonging to the same basin of attraction as the existed approaches based on the state observer for synchronizing chaotic systems. The approach is more robust against noise and parameter mismatch than the existed approaches based on the state observer for synchronizing chaotic systems, because the former uses variable structure control, which is strong robust with respect to noise and parameter mismatch in the error dynamics, the later uses an appropriate choice of the feedback gain. Two well-known chaotic systems, a chaotic Roessler system and a hyperchaotic Roessler system are considered as illustrative examples to demonstrate the effectiveness of the used approach by numerical simulations

  14. Time-Sharing-Based Synchronization and Performance Evaluation of Color-Independent Visual-MIMO Communication.

    Science.gov (United States)

    Kwon, Tae-Ho; Kim, Jai-Eun; Kim, Ki-Doo

    2018-05-14

    In the field of communication, synchronization is always an important issue. The communication between a light-emitting diode (LED) array (LEA) and a camera is known as visual multiple-input multiple-output (MIMO), for which the data transmitter and receiver must be synchronized for seamless communication. In visual-MIMO, LEDs generally have a faster data rate than the camera. Hence, we propose an effective time-sharing-based synchronization technique with its color-independent characteristics providing the key to overcome this synchronization problem in visual-MIMO communication. We also evaluated the performance of our synchronization technique by varying the distance between the LEA and camera. A graphical analysis is also presented to compare the symbol error rate (SER) at different distances.

  15. Global trends in satellite-based emergency mapping

    Science.gov (United States)

    Voigt, Stefan; Giulio-Tonolo, Fabio; Lyons, Josh; Kučera, Jan; Jones, Brenda; Schneiderhan, Tobias; Platzeck, Gabriel; Kaku, Kazuya; Hazarika, Manzul Kumar; Czaran, Lorant; Li, Suju; Pedersen, Wendi; James, Godstime Kadiri; Proy, Catherine; Muthike, Denis Macharia; Bequignon, Jerome; Guha-Sapir, Debarati

    2016-01-01

    Over the past 15 years, scientists and disaster responders have increasingly used satellite-based Earth observations for global rapid assessment of disaster situations. We review global trends in satellite rapid response and emergency mapping from 2000 to 2014, analyzing more than 1000 incidents in which satellite monitoring was used for assessing major disaster situations. We provide a synthesis of spatial patterns and temporal trends in global satellite emergency mapping efforts and show that satellite-based emergency mapping is most intensively deployed in Asia and Europe and follows well the geographic, physical, and temporal distributions of global natural disasters. We present an outlook on the future use of Earth observation technology for disaster response and mitigation by putting past and current developments into context and perspective.

  16. Synchronous Design and Test of Distributed Passive Radar Systems Based on Digital Broadcasting and Television

    Directory of Open Access Journals (Sweden)

    Wan Xianrong

    2017-02-01

    Full Text Available Digital broadcasting and television are important classes of illuminators of opportunity for passive radars. Distributed and multistatic structure are the development trends for passive radars. Most modern digital broadcasting and television systems work on a network, which not only provides a natural condition to distributed passive radar but also puts forward higher requirements on the design of passive radar systems. Among those requirements, precise synchronization among the receivers and transmitters as well as among multiple receiving stations, which mainly involves frequency and time synchronization, is the first to be solved. To satisfy the synchronization requirements of distributed passive radars, a synchronization scheme based on GPS is presented in this paper. Moreover, an effective scheme based on the China Mobile Multimedia Broadcasting signal is proposed to test the system synchronization performance. Finally, the reliability of the synchronization design is verified via the distributed multistatic passive radar experiments.

  17. Event-based cluster synchronization of coupled genetic regulatory networks

    Science.gov (United States)

    Yue, Dandan; Guan, Zhi-Hong; Li, Tao; Liao, Rui-Quan; Liu, Feng; Lai, Qiang

    2017-09-01

    In this paper, the cluster synchronization of coupled genetic regulatory networks with a directed topology is studied by using the event-based strategy and pinning control. An event-triggered condition with a threshold consisting of the neighbors' discrete states at their own event time instants and a state-independent exponential decay function is proposed. The intra-cluster states information and extra-cluster states information are involved in the threshold in different ways. By using the Lyapunov function approach and the theories of matrices and inequalities, we establish the cluster synchronization criterion. It is shown that both the avoidance of continuous transmission of information and the exclusion of the Zeno behavior are ensured under the presented triggering condition. Explicit conditions on the parameters in the threshold are obtained for synchronization. The stability criterion of a single GRN is also given under the reduced triggering condition. Numerical examples are provided to validate the theoretical results.

  18. Hierarchical-control-based output synchronization of coexisting attractor networks

    International Nuclear Information System (INIS)

    Yun-Zhong, Song; Yi-Fa, Tang

    2010-01-01

    This paper introduces the concept of hierarchical-control-based output synchronization of coexisting attractor networks. Within the new framework, each dynamic node is made passive at first utilizing intra-control around its own arena. Then each dynamic node is viewed as one agent, and on account of that, the solution of output synchronization of coexisting attractor networks is transformed into a multi-agent consensus problem, which is made possible by virtue of local interaction between individual neighbours; this distributed working way of coordination is coined as inter-control, which is only specified by the topological structure of the network. Provided that the network is connected and balanced, the output synchronization would come true naturally via synergy between intra and inter-control actions, where the Tightness is proved theoretically via convex composite Lyapunov functions. For completeness, several illustrative examples are presented to further elucidate the novelty and efficacy of the proposed scheme. (general)

  19. A Multimedia Tutorial for Charged-Particle Beam Dynamics. Final report

    International Nuclear Information System (INIS)

    Silbar, Richard R.

    1999-01-01

    In September 1995 WhistleSoft, Inc., began developing a computer-based multimedia tutorial for charged-particle beam dynamics under Phase II of a Small Business Innovative Research grant from the U.S. Department of Energy. In Phase I of this project (see its Final Report) we had developed several prototype multimedia modules using an authoring system on NeXTStep computers. Such a platform was never our intended target, and when we began Phase II we decided to make the change immediately to develop our tutorial modules for the Windows and Macintosh microcomputer market. This Report details our progress and accomplishments. It also gives a flavor of the look and feel of the presently available and upcoming modules

  20. A Multimedia Tutorial for Charged-Particle Beam Dynamics. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Silbar, Richard R.

    1999-07-26

    In September 1995 WhistleSoft, Inc., began developing a computer-based multimedia tutorial for charged-particle beam dynamics under Phase II of a Small Business Innovative Research grant from the U.S. Department of Energy. In Phase I of this project (see its Final Report) we had developed several prototype multimedia modules using an authoring system on NeXTStep computers. Such a platform was never our intended target, and when we began Phase II we decided to make the change immediately to develop our tutorial modules for the Windows and Macintosh microcomputer market. This Report details our progress and accomplishments. It also gives a flavor of the look and feel of the presently available and upcoming modules.

  1. Challenge of engaging all students via self-paced interactive electronic learning tutorials for introductory physics

    Directory of Open Access Journals (Sweden)

    Seth DeVore

    2017-05-01

    Full Text Available As research-based, self-paced electronic learning tools become increasingly available, a critical issue educators encounter is implementing strategies to ensure that all students engage with them as intended. Here, we first discuss the effectiveness of electronic learning tutorials as self-paced learning tools in large enrollment brick and mortar introductory physics courses and then propose a framework for helping students engage effectively with the learning tools. The tutorials were developed via research in physics education and were found to be effective for a diverse group of introductory physics students in one-on-one implementation. Instructors encouraged the use of these tools in a self-paced learning environment by telling students that they would be helpful for solving the assigned homework problems and that the underlying physics principles in the tutorial problems would be similar to those in the in-class quizzes (which we call paired problems. We find that many students in the courses in which these interactive electronic learning tutorials were assigned as a self-study tool performed poorly on the paired problems. In contrast, a majority of student volunteers in one-on-one implementation greatly benefited from the tutorials and performed well on the paired problems. The significantly lower overall performance on paired problems administered as an in-class quiz compared to the performance of student volunteers who used the research-based tutorials in one-on-one implementation suggests that many students enrolled in introductory physics courses did not effectively engage with the tutorials outside of class and may have only used them superficially. The findings suggest that many students in need of out-of-class remediation via self-paced learning tools may have difficulty motivating themselves and may lack the self-regulation and time-management skills to engage effectively with tools specially designed to help them learn at their

  2. Challenge of engaging all students via self-paced interactive electronic learning tutorials for introductory physics

    Science.gov (United States)

    DeVore, Seth; Marshman, Emily; Singh, Chandralekha

    2017-06-01

    As research-based, self-paced electronic learning tools become increasingly available, a critical issue educators encounter is implementing strategies to ensure that all students engage with them as intended. Here, we first discuss the effectiveness of electronic learning tutorials as self-paced learning tools in large enrollment brick and mortar introductory physics courses and then propose a framework for helping students engage effectively with the learning tools. The tutorials were developed via research in physics education and were found to be effective for a diverse group of introductory physics students in one-on-one implementation. Instructors encouraged the use of these tools in a self-paced learning environment by telling students that they would be helpful for solving the assigned homework problems and that the underlying physics principles in the tutorial problems would be similar to those in the in-class quizzes (which we call paired problems). We find that many students in the courses in which these interactive electronic learning tutorials were assigned as a self-study tool performed poorly on the paired problems. In contrast, a majority of student volunteers in one-on-one implementation greatly benefited from the tutorials and performed well on the paired problems. The significantly lower overall performance on paired problems administered as an in-class quiz compared to the performance of student volunteers who used the research-based tutorials in one-on-one implementation suggests that many students enrolled in introductory physics courses did not effectively engage with the tutorials outside of class and may have only used them superficially. The findings suggest that many students in need of out-of-class remediation via self-paced learning tools may have difficulty motivating themselves and may lack the self-regulation and time-management skills to engage effectively with tools specially designed to help them learn at their own pace. We

  3. On the synchronization of a class of chaotic systems based on backstepping method

    International Nuclear Information System (INIS)

    Wang Bo; Wen Guangjun

    2007-01-01

    This Letter focuses on the synchronization problem of a class of chaotic systems. A synchronization method is presented based on Lyapunov method and backstepping method. Finally some typical numerical examples are given to show the effectiveness of the theoretical results

  4. A Bidirectional Generalized Synchronization Theorem-Based Chaotic Pseudo-random Number Generator

    Directory of Open Access Journals (Sweden)

    Han Shuangshuang

    2013-07-01

    Full Text Available Based on a bidirectional generalized synchronization theorem for discrete chaos system, this paper introduces a new 5-dimensional bidirectional generalized chaos synchronization system (BGCSDS, whose prototype is a novel chaotic system introduced in [12]. Numerical simulation showed that two pair variables of the BGCSDS achieve generalized chaos synchronization via a transform H.A chaos-based pseudo-random number generator (CPNG was designed by the new BGCSDS. Using the FIPS-140-2 tests issued by the National Institute of Standard and Technology (NIST verified the randomness of the 1000 binary number sequences generated via the CPNG and the RC4 algorithm respectively. The results showed that all the tested sequences passed the FIPS-140-2 tests. The confidence interval analysis showed the statistical properties of the randomness of the sequences generated via the CPNG and the RC4 algorithm do not have significant differences.

  5. Impulsive Synchronization and Adaptive-Impulsive Synchronization of a Novel Financial Hyperchaotic System

    Directory of Open Access Journals (Sweden)

    Xiuli Chai

    2013-01-01

    Full Text Available The impulsive synchronization and adaptive-impulsive synchronization of a novel financial hyperchaotic system are investigated. Based on comparing principle for impulsive functional differential equations, several sufficient conditions for impulsive synchronization are derived, and the upper bounds of impulsive interval for stable synchronization are estimated. Furthermore, a nonlinear adaptive-impulsive control scheme is designed to synchronize the financial system using invariant principle of impulsive dynamical systems. Moreover, corresponding numerical simulations are presented to illustrate the effectiveness and feasibility of the proposed methods.

  6. Fixed-time synchronization of memristor-based BAM neural networks with time-varying discrete delay.

    Science.gov (United States)

    Chen, Chuan; Li, Lixiang; Peng, Haipeng; Yang, Yixian

    2017-12-01

    This paper is devoted to studying the fixed-time synchronization of memristor-based BAM neural networks (MBAMNNs) with discrete delay. Fixed-time synchronization means that synchronization can be achieved in a fixed time for any initial values of the considered systems. In the light of the double-layer structure of MBAMNNs, we design two similar feedback controllers. Based on Lyapunov stability theories, several criteria are established to guarantee that the drive and response MBAMNNs can realize synchronization in a fixed time. In particular, by changing the parameters of controllers, this fixed time can be adjusted to some desired value in advance, irrespective of the initial values of MBAMNNs. Numerical simulations are included to validate the derived results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Chaos Control and Synchronization of Cellular Neural Network with Delays Based on OPNCL Control

    International Nuclear Information System (INIS)

    Qian, Tang; Xing-Yuan, Wang

    2010-01-01

    The problem of chaos control and complete synchronization of cellular neural network with delays is studied. Based on the open plus nonlinear closed loop (OPNCL) method, the control scheme and synchronization scheme are designed. Both the schemes can achieve the chaos control and complete synchronization of chaotic neural network respectively, and their validity is further verified by numerical simulation experiments. (general)

  8. Distributed Synchronization Technique for OFDMA-Based Wireless Mesh Networks Using a Bio-Inspired Algorithm

    Directory of Open Access Journals (Sweden)

    Mi Jeong Kim

    2015-07-01

    Full Text Available In this paper, a distributed synchronization technique based on a bio-inspired algorithm is proposed for an orthogonal frequency division multiple access (OFDMA-based wireless mesh network (WMN with a time difference of arrival. The proposed time- and frequency-synchronization technique uses only the signals received from the neighbor nodes, by considering the effect of the propagation delay between the nodes. It achieves a fast synchronization with a relatively low computational complexity because it is operated in a distributed manner, not requiring any feedback channel for the compensation of the propagation delays. In addition, a self-organization scheme that can be effectively used to construct 1-hop neighbor nodes is proposed for an OFDMA-based WMN with a large number of nodes. The performance of the proposed technique is evaluated with regard to the convergence property and synchronization success probability using a computer simulation.

  9. Distributed Synchronization Technique for OFDMA-Based Wireless Mesh Networks Using a Bio-Inspired Algorithm.

    Science.gov (United States)

    Kim, Mi Jeong; Maeng, Sung Joon; Cho, Yong Soo

    2015-07-28

    In this paper, a distributed synchronization technique based on a bio-inspired algorithm is proposed for an orthogonal frequency division multiple access (OFDMA)-based wireless mesh network (WMN) with a time difference of arrival. The proposed time- and frequency-synchronization technique uses only the signals received from the neighbor nodes, by considering the effect of the propagation delay between the nodes. It achieves a fast synchronization with a relatively low computational complexity because it is operated in a distributed manner, not requiring any feedback channel for the compensation of the propagation delays. In addition, a self-organization scheme that can be effectively used to construct 1-hop neighbor nodes is proposed for an OFDMA-based WMN with a large number of nodes. The performance of the proposed technique is evaluated with regard to the convergence property and synchronization success probability using a computer simulation.

  10. Synchronization for the uplink of OFDMA-based System

    DEFF Research Database (Denmark)

    Nguyen, Huan Cong

    2008-01-01

    are designed for single-user system, and therefore are not able to correct multiple CFOs in the uplink. The aim of this thesis is to provide practical solutions  for the synchronization issues occurring in the uplink of the OFDMA-based broadband wireless systems.  Several data-aided CFO estimation algorithms...

  11. SALIENCY BASED SEGMENTATION OF SATELLITE IMAGES

    Directory of Open Access Journals (Sweden)

    A. Sharma

    2015-03-01

    Full Text Available Saliency gives the way as humans see any image and saliency based segmentation can be eventually helpful in Psychovisual image interpretation. Keeping this in view few saliency models are used along with segmentation algorithm and only the salient segments from image have been extracted. The work is carried out for terrestrial images as well as for satellite images. The methodology used in this work extracts those segments from segmented image which are having higher or equal saliency value than a threshold value. Salient and non salient regions of image become foreground and background respectively and thus image gets separated. For carrying out this work a dataset of terrestrial images and Worldview 2 satellite images (sample data are used. Results show that those saliency models which works better for terrestrial images are not good enough for satellite image in terms of foreground and background separation. Foreground and background separation in terrestrial images is based on salient objects visible on the images whereas in satellite images this separation is based on salient area rather than salient objects.

  12. Synchronized Phasor Measurements of a Power System Event in Eastern Denmark

    DEFF Research Database (Denmark)

    Rasmussen, Joana; Jørgensen, Preben

    2003-01-01

    . The outage of the 400-kV tie-line weakened the Eastern Danish power system and excited power oscillations in the interconnected power systems. During this event prototype Phasor Measurements Units (PMU) gave the opportunity of realtime monitoring of positive sequence voltage and current phasors using...... satellite-based Global Positioning System (GPS). Comparisons between real-time recordings and results from dynamic simulations with PSS/E are presented. The main features from the simulation analysis are successfully verified by means of the corresponding synchronized phasor measurements....

  13. Synchronized Phasor Measurements of a Power System Event in Eastern Denmark

    DEFF Research Database (Denmark)

    Rasmussen, Joana; Jørgensen, Preben

    2006-01-01

    . The outage of the 400-kV tie-line weakened the Eastern Danish power system and excited power oscillations in the interconnected power systems. During this event prototype Phasor Measurements Units (PMU) gave the opportunity of realtime monitoring of positive sequence voltage and current phasors using...... satellite-based Global Positioning System (GPS). Comparisons between real-time recordings and results from dynamic simulations with PSS/E are presented. The main features from the simulation analysis are successfully verified by means of the corresponding synchronized phasor measurements....

  14. Developing and Testing a Video Tutorial for Software Training

    NARCIS (Netherlands)

    van der Meij, Hans

    2014-01-01

    Purpose: Video tutorials for software training are rapidly becoming popular. A set of dedicated guidelines for the construction of such tutorials was recently advanced in Technical Communication (Van der Meij & Van der Meij, 2013). The present study set out to assess the cognitive and motivational

  15. [Cardiac Synchronization Function Estimation Based on ASM Level Set Segmentation Method].

    Science.gov (United States)

    Zhang, Yaonan; Gao, Yuan; Tang, Liang; He, Ying; Zhang, Huie

    At present, there is no accurate and quantitative methods for the determination of cardiac mechanical synchronism, and quantitative determination of the synchronization function of the four cardiac cavities with medical images has a great clinical value. This paper uses the whole heart ultrasound image sequence, and segments the left & right atriums and left & right ventricles of each frame. After the segmentation, the number of pixels in each cavity and in each frame is recorded, and the areas of the four cavities of the image sequence are therefore obtained. The area change curves of the four cavities are further extracted, and the synchronous information of the four cavities is obtained. Because of the low SNR of Ultrasound images, the boundary lines of cardiac cavities are vague, so the extraction of cardiac contours is still a challenging problem. Therefore, the ASM model information is added to the traditional level set method to force the curve evolution process. According to the experimental results, the improved method improves the accuracy of the segmentation. Furthermore, based on the ventricular segmentation, the right and left ventricular systolic functions are evaluated, mainly according to the area changes. The synchronization of the four cavities of the heart is estimated based on the area changes and the volume changes.

  16. Writing learning cases for an information literacy tutorial

    Directory of Open Access Journals (Sweden)

    Gunhild Austrheim

    2010-09-01

    Full Text Available The research and writing processes are often hidden mysteries to our students. A key point in the online tutorial Search and Write (Søk and Skriv has been to supply our students with tools to handle these processes. Learning cases embedded in the tutorial allow us to demonstrate a variety of working techniques and to better cater for a diverse student population. The tutorial can be used as an independent resource for students and as a teaching aid for both library sessions on information literacy and for faculty-led sessions on academic writing. Our tutorial is available in Norwegian and in English and thereby the tutorial can be used with both local and international students. An online tutorial is aimed at all students and therefore the information literacy content is of a general kind. The pedagogical foundation for the Search and Write tutorial is in contextual learning. Adding context to our general content has been important to us and we decided to develop learning cases for this purpose. In our online tutorial we have developed three sample student blogs, Kuhlthau’s information search process functions as a template in structuring the students’ stories. The blogs are learning cases, developed with the intent of illustrating various aspects of academic writing tasks. The blog stories are idealized and touch upon many of the known stumbling stones for student writers. Contextualising the search and write process like this let us explore the diversity of student assignments and from various fields of study. When our real-life students use Search and Write they may use their own research question as a point of departure. They can read the blog stories and relate these stories to their own experiences. They can use the How to brainstorm-tips provided in Sofie’s blog. Christian’s use of tutors, library staff and his writing group can provide guidance on who to ask for help. For students writing literature reviews Oda’s systematic

  17. Underwater Time Service and Synchronization Based on Time Reversal Technique

    Science.gov (United States)

    Lu, Hao; Wang, Hai-bin; Aissa-El-Bey, Abdeldjalil; Pyndiah, Ramesh

    2010-09-01

    Real time service and synchronization are very important to many underwater systems. But the time service and synchronization in existence cannot work well due to the multi-path propagation and random phase fluctuation of signals in the ocean channel. The time reversal mirror technique can realize energy concentration through self-matching of the ocean channel and has very good spatial and temporal focusing properties. Based on the TRM technique, we present the Time Reversal Mirror Real Time service and synchronization (TRMRT) method which can bypass the processing of multi-path on the server side and reduce multi-path contamination on the client side. So TRMRT can improve the accuracy of time service. Furthermore, as an efficient and precise method of time service, TRMRT could be widely used in underwater exploration activities and underwater navigation and positioning systems.

  18. Strategies for satellite-based monitoring of CO2 from distributed area and point sources

    Science.gov (United States)

    Schwandner, Florian M.; Miller, Charles E.; Duren, Riley M.; Natraj, Vijay; Eldering, Annmarie; Gunson, Michael R.; Crisp, David

    2014-05-01

    and sensor provides the full range of temporal sampling needed to characterize distributed area and point source emissions. For instance, point source emission patterns will vary with source strength, wind speed and direction. Because wind speed, direction and other environmental factors change rapidly, short term variabilities should be sampled. For detailed target selection and pointing verification, important lessons have already been learned and strategies devised during JAXA's GOSAT mission (Schwandner et al, 2013). The fact that competing spatial and temporal requirements drive satellite remote sensing sampling strategies dictates a systematic, multi-factor consideration of potential solutions. Factors to consider include vista, revisit frequency, integration times, spatial resolution, and spatial coverage. No single satellite-based remote sensing solution can address this problem for all scales. It is therefore of paramount importance for the international community to develop and maintain a constellation of atmospheric CO2 monitoring satellites that complement each other in their temporal and spatial observation capabilities: Polar sun-synchronous orbits (fixed local solar time, no diurnal information) with agile pointing allow global sampling of known distributed area and point sources like megacities, power plants and volcanoes with daily to weekly temporal revisits and moderate to high spatial resolution. Extensive targeting of distributed area and point sources comes at the expense of reduced mapping or spatial coverage, and the important contextual information that comes with large-scale contiguous spatial sampling. Polar sun-synchronous orbits with push-broom swath-mapping but limited pointing agility may allow mapping of individual source plumes and their spatial variability, but will depend on fortuitous environmental conditions during the observing period. These solutions typically have longer times between revisits, limiting their ability to resolve

  19. Effectiveness of Tutorials for Introductory Physics in Argentinean high schools

    Science.gov (United States)

    Benegas, J.; Flores, J. Sirur

    2014-06-01

    This longitudinal study reports the results of a replication of Tutorials in Introductory Physics in high schools of a Latin-American country. The main objective of this study was to examine the suitability of Tutorials for local science education reform. Conceptual learning of simple resistive electric circuits was determined by the application of the single-response multiple-choice test "Determining and Interpreting Resistive Electric Circuits Concepts Test" (DIRECT) to high school classes taught with Tutorials and traditional instruction. The study included state and privately run schools of different socioeconomic profiles, without formal laboratory space and equipment, in classes of mixed-gender and female-only students, taught by novice and experienced instructors. Results systematically show that student learning is significantly higher in the Tutorials classes compared with traditional teaching for all of the studied conditions. The results also show that long-term learning (one year after instruction) in the Tutorials classes is highly satisfactory, very similar to the performance of the samples of college students used to develop the test DIRECT. On the contrary, students following traditional instruction returned one year after instruction to the poor performance (students attending seven universities in Spain and four Latin-American countries. Some replication and adaptation problems and difficulties of this experience are noted, as well as recommendations for successful use of Tutorials in high schools of similar educational systems.

  20. Master-slave exponential synchronization of delayed complex-valued memristor-based neural networks via impulsive control.

    Science.gov (United States)

    Li, Xiaofan; Fang, Jian-An; Li, Huiyuan

    2017-09-01

    This paper investigates master-slave exponential synchronization for a class of complex-valued memristor-based neural networks with time-varying delays via discontinuous impulsive control. Firstly, the master and slave complex-valued memristor-based neural networks with time-varying delays are translated to two real-valued memristor-based neural networks. Secondly, an impulsive control law is constructed and utilized to guarantee master-slave exponential synchronization of the neural networks. Thirdly, the master-slave synchronization problems are transformed into the stability problems of the master-slave error system. By employing linear matrix inequality (LMI) technique and constructing an appropriate Lyapunov-Krasovskii functional, some sufficient synchronization criteria are derived. Finally, a numerical simulation is provided to illustrate the effectiveness of the obtained theoretical results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Fuzzy model-based adaptive synchronization of time-delayed chaotic systems

    International Nuclear Information System (INIS)

    Vasegh, Nastaran; Majd, Vahid Johari

    2009-01-01

    In this paper, fuzzy model-based synchronization of a class of first order chaotic systems described by delayed-differential equations is addressed. To design the fuzzy controller, the chaotic system is modeled by Takagi-Sugeno fuzzy system considering the properties of the nonlinear part of the system. Assuming that the parameters of the chaotic system are unknown, an adaptive law is derived to estimate these unknown parameters, and the stability of error dynamics is guaranteed by Lyapunov theory. Numerical examples are given to demonstrate the validity of the proposed adaptive synchronization approach.

  2. Spatial and temporal interpolation of satellite-based aerosol optical depth measurements over North America using B-splines

    Science.gov (United States)

    Pfister, Nicolas; O'Neill, Norman T.; Aube, Martin; Nguyen, Minh-Nghia; Bechamp-Laganiere, Xavier; Besnier, Albert; Corriveau, Louis; Gasse, Geremie; Levert, Etienne; Plante, Danick

    2005-08-01

    Satellite-based measurements of aerosol optical depth (AOD) over land are obtained from an inversion procedure applied to dense dark vegetation pixels of remotely sensed images. The limited number of pixels over which the inversion procedure can be applied leaves many areas with little or no AOD data. Moreover, satellite coverage by sensors such as MODIS yields only daily images of a given region with four sequential overpasses required to straddle mid-latitude North America. Ground based AOD data from AERONET sun photometers are available on a more continuous basis but only at approximately fifty locations throughout North America. The object of this work is to produce a complete and coherent mapping of AOD over North America with a spatial resolution of 0.1 degree and a frequency of three hours by interpolating MODIS satellite-based data together with available AERONET ground based measurements. Before being interpolated, the MODIS AOD data extracted from different passes are synchronized to the mapping time using analyzed wind fields from the Global Multiscale Model (Meteorological Service of Canada). This approach amounts to a trajectory type of simplified atmospheric dynamics correction method. The spatial interpolation is performed using a weighted least squares method applied to bicubic B-spline functions defined on a rectangular grid. The least squares method enables one to weight the data accordingly to the measurement errors while the B-splines properties of local support and C2 continuity offer a good approximation of AOD behaviour viewed as a function of time and space.

  3. Comparison of two interactive tutorial methods: results from a medical college in Karachi.

    Science.gov (United States)

    Rehan, Rabiya; Farooqi, Lubna; Khan, Hira; Rehman, Rehana

    2017-02-01

    To compare perception of students on usefulness of interactive tutorials and clinically-oriented problem-solving tutorials. The cross-sectional study was carried out from January 2012 to November 2013 at Bahria University Medical and Dental College, Karachi. The perception of medical students on usefulness of interactive tutorials and clinically-oriented problem-solving tutorials was acquired through a questionnaire distributed to medical students having completed the first two years of studies. The responses on various aspects of learning of physiology were acquired on a scale of poor, good or excellent. The learning abilities and acquired skills were compared in terms of not at all, to some extent, and to great extent. Data was analysed using SPSS 15. Of the hundred students initially enrolled, complete response was obtained from 83(83%). Of them, 47(57%) were females. There was significant difference in understanding of structure and function by clinically-oriented problem-solving tutorials (p=0.04). The students preferred clinically-oriented problem-solving tutorials as far as understating of difficult concepts was concerned (pskills were improved by interactive tutorials (p=0.02) whereas clinical reasoning skills acquired by clinically-oriented problem-solving tutorials was found to be significantly better (pskills were acquired more by clinically-oriented problem-solving tutorials that helped in better understanding of structure and functions.

  4. Synchronicity from Synchronized Chaos

    Directory of Open Access Journals (Sweden)

    Gregory S. Duane

    2015-03-01

    Full Text Available The synchronization of loosely-coupled chaotic oscillators, a phenomenon investigated intensively for the last two decades, may realize the philosophical concept of “synchronicity”—the commonplace notion that related eventsmysteriously occur at the same time. When extended to continuous media and/or large discrete arrays, and when general (non-identical correspondences are considered between states, intermittent synchronous relationships indeed become ubiquitous. Meaningful synchronicity follows naturally if meaningful events are identified with coherent structures, defined by internal synchronization between remote degrees of freedom; a condition that has been posited as necessary for synchronizability with an external system. The important case of synchronization between mind and matter is realized if mind is analogized to a computer model, synchronizing with a sporadically observed system, as in meteorological data assimilation. Evidence for the ubiquity of synchronization is reviewed along with recent proposals that: (1 synchronization of different models of the same objective process may be an expeditious route to improved computational modeling and may also describe the functioning of conscious brains; and (2 the nonlocality in quantum phenomena implied by Bell’s theorem may be explained in a variety of deterministic (hidden variable interpretations if the quantum world resides on a generalized synchronization “manifold”.

  5. Parameter Identification and Synchronization of Uncertain Chaotic Systems Based on Sliding Mode Observer

    Directory of Open Access Journals (Sweden)

    Li-lian Huang

    2013-01-01

    Full Text Available The synchronization of nonlinear uncertain chaotic systems is investigated. We propose a sliding mode state observer scheme which combines the sliding mode control with observer theory and apply it into the uncertain chaotic system with unknown parameters and bounded interference. Based on Lyapunov stability theory, the constraints of synchronization and proof are given. This method not only can realize the synchronization of chaotic systems, but also identify the unknown parameters and obtain the correct parameter estimation. Otherwise, the synchronization of chaotic systems with unknown parameters and bounded external disturbances is robust by the design of the sliding surface. Finally, numerical simulations on Liu chaotic system with unknown parameters and disturbances are carried out. Simulation results show that this synchronization and parameter identification has been totally achieved and the effectiveness is verified very well.

  6. MacSelfService online tutorial

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Mac Self-Service is a functionality within the Mac Desktop Service built and maintained to empower CERN users by giving them easy access to applications and configurations through the Self-Service application. This tutorial (text attached to the event page) explains how to install Mac Self-Service and how to use it to install applications and printers. Content owner: Vincent Nicolas Bippus Presenter: Pedro Augusto de Freitas Batista Tell us what you think via e-learning.support at cern.ch More tutorials in the e-learning collection of the CERN Document Server (CDS) https://cds.cern.ch/collection/E-learning%20modules?ln=en All info about the CERN rapid e-learning project is linked from http://twiki.cern.ch/ELearning  

  7. Improving the University Tutorial.

    Science.gov (United States)

    Stanton, Harry E.

    1982-01-01

    Frequently, tutorial or seminar members take no part in discussion, a feature considered essential to this teaching method. Tutors may be largely responsible by dominating discussion. Student participation can be increased by varying teaching methods; reducing discussion group size, brainstorming, idea development techniques, and student…

  8. Tutorial to SARAH

    CERN Document Server

    Staub, Florian

    2016-01-01

    I give in this brief tutorial a short practical introduction to the Mathematica package SARAH. First, it is shown how an existing model file can be changed to implement a new model in SARAH. In the second part, masses, vertices and renormalisation group equations are calculated with SARAH. Finally, the main commands to generate model files and output for other tools are summarised.

  9. Parameterization of Fuel-Optimal Synchronous Approach Trajectories to Tumbling Targets

    Directory of Open Access Journals (Sweden)

    David Charles Sternberg

    2018-04-01

    Full Text Available Docking with potentially tumbling Targets is a common element of many mission architectures, including on-orbit servicing and active debris removal. This paper studies synchronized docking trajectories as a way to ensure the Chaser satellite remains on the docking axis of the tumbling Target, thereby reducing collision risks and enabling persistent onboard sensing of the docking location. Chaser satellites have limited computational power available to them and the time allowed for the determination of a fuel optimal trajectory may be limited. Consequently, parameterized trajectories that approximate the fuel optimal trajectory while following synchronous approaches may be used to provide a computationally efficient means of determining near optimal trajectories to a tumbling Target. This paper presents a method of balancing the computation cost with the added fuel expenditure required for parameterization, including the selection of a parameterization scheme, the number of parameters in the parameterization, and a means of incorporating the dynamics of a tumbling satellite into the parameterization process. Comparisons of the parameterized trajectories are made with the fuel optimal trajectory, which is computed through the numerical propagation of Euler’s equations. Additionally, various tumble types are considered to demonstrate the efficacy of the presented computation scheme. With this parameterized trajectory determination method, Chaser satellites may perform terminal approach and docking maneuvers with both fuel and computational efficiency.

  10. The Effectiveness of a 3D Computerized Tutorial to Enhance Learning of the Canine Larynx and Hyoid Apparatus.

    Science.gov (United States)

    Nemanic, Sarah; Mills, Serena; Viehdorfer, Matt; Clark, Terri; Bailey, Mike

    Teaching the anatomy of the canine larynx and hyoid apparatus is challenging because dissection disassembles and/or damages these structures, making it difficult to understand their three-dimensional (3D) anatomy and spatial interrelationships. This study assessed the effectiveness of an interactive, computerized 3D tutorial for teaching the anatomy of the canine larynx and hyoid apparatus using a randomized control design with students enrolled in the first-year professional program at Oregon State University College of Veterinary Medicine. All first-year students from 2 consecutive years were eligible. All students received the traditional methods of didactic teaching and dissection to learn the anatomy of the canine larynx and hyoid apparatus, after which they were divided into two statistically equal groups based on their cumulative anatomy test scores from the prior term. The tutorial group received an interactive, computerized tutorial developed by the investigators containing 3D images of the canine larynx and hyoid apparatus, while the control group received the same 3D images without the computerized tutorial. Both groups received the same post-learning assessment and survey. Sixty-three first-year students participated in the study, 28 in the tutorial group, and 35 in the control group. Post-learning assessment and survey scores were both significantly higher among students in the computerized tutorial group than those in the control group. This study demonstrates that a 3D computerized tutorial is more effective in teaching the anatomy of the canine hyoid apparatus and larynx than 3D images without a tutorial. Students likewise rated their learning experience higher when using the 3D computerized tutorial.

  11. Parameter identification based synchronization for a class of chaotic systems with offset vectors

    International Nuclear Information System (INIS)

    Chen Cailian; Feng Gang; Guan Xinping

    2004-01-01

    Based on a parameter identification scheme, a novel synchronization method is presented for a class of chaotic systems with offset vectors which can be represented by the so-called T-S fuzzy model. It is shown that the slave system can synchronize the master system and the unknown parameters of the master system can be identified simultaneously. The delayed feedback technique is also developed in order to reduce the energy and time required for the identification and synchronization. Numerical simulations demonstrate the effectiveness of the proposed method

  12. Time synchronization algorithm of distributed system based on server time-revise and workstation self-adjust

    International Nuclear Information System (INIS)

    Zhou Shumin; Sun Yamin; Tang Bin

    2007-01-01

    In order to enhance the time synchronization quality of the distributed system, a time synchronization algorithm of distributed system based on server time-revise and workstation self-adjust is proposed. The time-revise cycle and self-adjust process is introduced in the paper. The algorithm reduces network flow effectively and enhances the quality of clock-synchronization. (authors)

  13. Japanese Global Precipitation Measurement (GPM) mission status and application of satellite-based global rainfall map

    Science.gov (United States)

    Kachi, Misako; Shimizu, Shuji; Kubota, Takuji; Yoshida, Naofumi; Oki, Riko; Kojima, Masahiro; Iguchi, Toshio; Nakamura, Kenji

    2010-05-01

    As accuracy of satellite precipitation estimates improves and observation frequency increases, application of those data to societal benefit areas, such as weather forecasts and flood predictions, is expected, in addition to research of precipitation climatology to analyze precipitation systems. There is, however, limitation on single satellite observation in coverage and frequency. Currently, the Global Precipitation Measurement (GPM) mission is scheduled under international collaboration to fulfill various user requirements that cannot be achieved by the single satellite, like the Tropical Rainfall Measurement Mission (TRMM). The GPM mission is an international mission to achieve high-accurate and high-frequent rainfall observation over a global area. GPM is composed of a TRMM-like non-sun-synchronous orbit satellite (GPM core satellite) and constellation of satellites carrying microwave radiometer instruments. The GPM core satellite carries the Dual-frequency Precipitation Radar (DPR), which is being developed by the Japan Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT), and microwave radiometer provided by the National Aeronautics and Space Administration (NASA). Development of DPR instrument is in good progress for scheduled launch in 2013, and DPR Critical Design Review has completed in July - September 2009. Constellation satellites, which carry a microwave imager and/or sounder, are planned to be launched around 2013 by each partner agency for its own purpose, and will contribute to extending coverage and increasing frequency. JAXA's future mission, the Global Change Observation Mission (GCOM) - Water (GCOM-W) satellite will be one of constellation satellites. The first generation of GCOM-W satellite is scheduled to be launched in 2011, and it carries the Advanced Microwave Scanning Radiometer 2 (AMSR2), which is being developed based on the experience of the AMSR-E on EOS Aqua satellite

  14. Spontaneous Synchronization in Two Mutually Coupled Memristor-Based Chua’s Circuits: Numerical Investigations

    Directory of Open Access Journals (Sweden)

    Eleonora Bilotta

    2014-01-01

    Full Text Available Chaotic dynamics of numerous memristor-based circuits is widely reported in literature. Recently, some works have appeared which study the problem of synchronization control of these systems in a master-slave configuration. In the present paper, the spontaneous dynamic behavior of two chaotic memristor-based Chua’s circuits, mutually interacting through a coupling resistance, was studied via computer simulations in order to study possible self-organized synchronization phenomena. The used memristor is a flux controlled memristor with a cubic nonlinearity, and it can be regarded as a time-varying memductance. The memristor, in effect, retains memory of its past dynamic and any difference in the initial conditions of the two circuits results in different values of the corresponding memductances. In this sense, due to the memory effect of the memristor, even if coupled circuits have the same parameters they do not constitute two completely identical chaotic oscillators. As is known, for nonidentical chaotic systems, in addition to complete synchronizations (CS other weaker forms of synchronization which provide correlations between the signals of the two systems can also occur. Depending on initial conditions and coupling strength, both chaotic and nonchaotic synchronization are observed for the system considered in this work.

  15. Tidal synchronization of an anelastic multi-layered body: Titan's synchronous rotation

    Science.gov (United States)

    Folonier, Hugo A.; Ferraz-Mello, Sylvio

    2017-12-01

    Tidal torque drives the rotational and orbital evolution of planet-satellite and star-exoplanet systems. This paper presents one analytical tidal theory for a viscoelastic multi-layered body with an arbitrary number of homogeneous layers. Starting with the static equilibrium figure, modified to include tide and differential rotation, and using the Newtonian creep approach, we find the dynamical equilibrium figure of the deformed body, which allows us to calculate the tidal potential and the forces acting on the tide generating body, as well as the rotation and orbital elements variations. In the particular case of the two-layer model, we study the tidal synchronization when the gravitational coupling and the friction in the interface between the layers is added. For high relaxation factors (low viscosity), the stationary solution of each layer is synchronous with the orbital mean motion ( n) when the orbit is circular, but the rotational frequencies increase if the orbital eccentricity increases. This behavior is characteristic in the classical Darwinian theories and in the homogeneous case of the creep tide theory. For low relaxation factors (high viscosity), as in planetary satellites, if friction remains low, each layer can be trapped in different spin-orbit resonances with frequencies n/2,n,3n/2,2n,\\ldots . When the friction increases, attractors with differential rotations are destroyed, surviving only commensurabilities in which core and shell have the same velocity of rotation. We apply the theory to Titan. The main results are: (i) the rotational constraint does not allow us to confirm or reject the existence of a subsurface ocean in Titan; and (ii) the crust-atmosphere exchange of angular momentum can be neglected. Using the rotation estimate based on Cassini's observation (Meriggiola et al. in Icarus 275:183-192, 2016), we limit the possible value of the shell relaxation factor, when a deep subsurface ocean is assumed, to γ _s≲ 10^{-9} s^{-1}, which

  16. Ground test of satellite constellation based quantum communication

    OpenAIRE

    Liao, Sheng-Kai; Yong, Hai-Lin; Liu, Chang; Shentu, Guo-Liang; Li, Dong-Dong; Lin, Jin; Dai, Hui; Zhao, Shuang-Qiang; Li, Bo; Guan, Jian-Yu; Chen, Wei; Gong, Yun-Hong; Li, Yang; Lin, Ze-Hong; Pan, Ge-Sheng

    2016-01-01

    Satellite based quantum communication has been proven as a feasible way to achieve global scale quantum communication network. Very recently, a low-Earth-orbit (LEO) satellite has been launched for this purpose. However, with a single satellite, it takes an inefficient 3-day period to provide the worldwide connectivity. On the other hand, similar to how the Iridium system functions in classic communication, satellite constellation (SC) composed of many quantum satellites, could provide global...

  17. Cluster Synchronization of Diffusively Coupled Nonlinear Systems: A Contraction-Based Approach

    Science.gov (United States)

    Aminzare, Zahra; Dey, Biswadip; Davison, Elizabeth N.; Leonard, Naomi Ehrich

    2018-04-01

    Finding the conditions that foster synchronization in networked nonlinear systems is critical to understanding a wide range of biological and mechanical systems. However, the conditions proved in the literature for synchronization in nonlinear systems with linear coupling, such as has been used to model neuronal networks, are in general not strict enough to accurately determine the system behavior. We leverage contraction theory to derive new sufficient conditions for cluster synchronization in terms of the network structure, for a network where the intrinsic nonlinear dynamics of each node may differ. Our result requires that network connections satisfy a cluster-input-equivalence condition, and we explore the influence of this requirement on network dynamics. For application to networks of nodes with FitzHugh-Nagumo dynamics, we show that our new sufficient condition is tighter than those found in previous analyses that used smooth or nonsmooth Lyapunov functions. Improving the analytical conditions for when cluster synchronization will occur based on network configuration is a significant step toward facilitating understanding and control of complex networked systems.

  18. Past, Present and Future Aspects of Laser-Based Synchronization at FLASH

    OpenAIRE

    Schulz, Sebastian; Bousonville, Michael; Steffen, Bernd; Sydlo, Cezary; Zummack, Falco; Kozak, Tomasz; Predki, Pawel; Kuhl, Alexander; Czwalinna, Marie Kristin; Felber, Matthias; Heuer, Michael; Lamb, Thorsten; Mueller, Jost; Peier, Peter; Ruzin, Sergej

    2013-01-01

    Free-electron lasers, like FLASH and the upcoming European XFEL, are capable of producing XUV and X-ray pulses of a few femtoseconds duration. For time-resolved pump-probe experiments and the externally seeded operation mode it is crucial not only to stabilize the arrival time of the electron bunches, but also to achieve a synchronization accuracy of external lasers on the same timescale. This can only be realized with a laser-based synchronization infrastructure. At FLASH, a periodic femtose...

  19. The Development of e-tutorial on Implementation National Curriculum 2013 for Mathematics Teacher

    Science.gov (United States)

    Roza, Yenita; Satria, Gita; Nur Siregar, Syarifah

    2017-06-01

    Curriculum 2013 is the new national Curriculum in Indonesia that is targeted to be used in all Indonesian schools in 2019. At this time the teacher training continues but the number and locations of teachers very diffuse and time constraints to be an obstacle for the government to be able to conduct training for teachers. This research resulted in the e-tutorial which is designed for mathematics teachers in studying the process of Curriculum implementation. This product will assist the government in accelerating the preparation of teachers in implementation of Curriculum 2013. This e-tutorial contains the dynamics of Curriculum development, learning model, learning assessment, lesson plan, curriculum stages of implementation and government regulation that is relevant to the implementation of Curriculum 2013. The product development started with a needs analysis through discussions with mathematics teachers about their difficulties in the implementation of the Curriculum 2013. This e-tutorial was developed using Application of Adobe Director 11. This paper discusses the results of need analysis, process development and results of product revisions made based on input from teachers during the FGD. From the discussion, it can be concluded that this e-tutorial easily understood by teachers and help them to understand the implementation of Curriculum 2013

  20. Diagnostics of synchronous motor based on analysis of acoustic signals with application of MFCC and Nearest Mean classifier

    OpenAIRE

    Adam Głowacz; Witold Głowacz; Andrzej Głowacz

    2010-01-01

    The paper presents method of diagnostics of imminent failure conditions of synchronous motor. This method is based on a study ofacoustic signals generated by synchronous motor. Sound recognition system is based on algorithms of data processing, such as MFCC andNearest Mean classifier with cosine distance. Software to recognize the sounds of synchronous motor was implemented. The studies werecarried out for four imminent failure conditions of synchronous motor. The results confirm that the sys...

  1. Statistical Shape Modelling and Markov Random Field Restoration (invited tutorial and exercise)

    DEFF Research Database (Denmark)

    Hilger, Klaus Baggesen

    This tutorial focuses on statistical shape analysis using point distribution models (PDM) which is widely used in modelling biological shape variability over a set of annotated training data. Furthermore, Active Shape Models (ASM) and Active Appearance Models (AAM) are based on PDMs and have proven...... deformation field between shapes. The tutorial demonstrates both generative active shape and appearance models, and MRF restoration on 3D polygonized surfaces. ''Exercise: Spectral-Spatial classification of multivariate images'' From annotated training data this exercise applies spatial image restoration...... using Markov random field relaxation of a spectral classifier. Keywords: the Ising model, the Potts model, stochastic sampling, discriminant analysis, expectation maximization....

  2. Interactive video tutorials for enhancing problem solving, reasoning, and meta-cognitive skills of introductory physics students

    OpenAIRE

    Singh, Chandralekha

    2016-01-01

    We discuss the development of interactive video tutorial-based problems to help introductory physics students learn effective problem solving heuristics. The video tutorials present problem solving strategies using concrete examples in an interactive environment. They force students to follow a systematic approach to problem solving and students are required to solve sub-problems (research-guided multiple choice questions) to show their level of understanding at every stage of prob lem solvin...

  3. Image Positioning Accuracy Analysis for Super Low Altitude Remote Sensing Satellites

    Directory of Open Access Journals (Sweden)

    Ming Xu

    2012-10-01

    Full Text Available Super low altitude remote sensing satellites maintain lower flight altitudes by means of ion propulsion in order to improve image resolution and positioning accuracy. The use of engineering data in design for achieving image positioning accuracy is discussed in this paper based on the principles of the photogrammetry theory. The exact line-of-sight rebuilding of each detection element and this direction precisely intersecting with the Earth's elliptical when the camera on the satellite is imaging are both ensured by the combined design of key parameters. These parameters include: orbit determination accuracy, attitude determination accuracy, camera exposure time, accurately synchronizing the reception of ephemeris with attitude data, geometric calibration and precise orbit verification. Precise simulation calculations show that image positioning accuracy of super low altitude remote sensing satellites is not obviously improved. The attitude determination error of a satellite still restricts its positioning accuracy.

  4. Making Accounting Tutorials Enjoyable

    Science.gov (United States)

    Bargate, Karen

    2018-01-01

    This paper emanates from a case study which focussed on 15 Managerial Accounting and Financial Management (MAFM) students' "enjoyment" of learning MAFM in an 18-week Writing Intensive Tutorial (WIT) programme. Interactive Qualitative Analysis (IQA) was used for the research design and as a data analysis tool. Following IQA protocols…

  5. Effectiveness of Tutorials for Introductory Physics in Argentinean high schools

    Directory of Open Access Journals (Sweden)

    J. Benegas

    2014-03-01

    Full Text Available This longitudinal study reports the results of a replication of Tutorials in Introductory Physics in high schools of a Latin-American country. The main objective of this study was to examine the suitability of Tutorials for local science education reform. Conceptual learning of simple resistive electric circuits was determined by the application of the single-response multiple-choice test “Determining and Interpreting Resistive Electric Circuits Concepts Test” (DIRECT to high school classes taught with Tutorials and traditional instruction. The study included state and privately run schools of different socioeconomic profiles, without formal laboratory space and equipment, in classes of mixed-gender and female-only students, taught by novice and experienced instructors. Results systematically show that student learning is significantly higher in the Tutorials classes compared with traditional teaching for all of the studied conditions. The results also show that long-term learning (one year after instruction in the Tutorials classes is highly satisfactory, very similar to the performance of the samples of college students used to develop the test DIRECT. On the contrary, students following traditional instruction returned one year after instruction to the poor performance (<20% shown before instruction, a result compatible with the very low level of conceptual knowledge of basic physics recently determined by a systematic study of first-year students attending seven universities in Spain and four Latin-American countries. Some replication and adaptation problems and difficulties of this experience are noted, as well as recommendations for successful use of Tutorials in high schools of similar educational systems.

  6. Benefits from Taking a Private Tutorial Course for Exam Preparation?

    DEFF Research Database (Denmark)

    la Cour, Lisbeth; Milhøj, Anders

    course in order to perform well at the exam but still more than 50 % of a cohort signs up for the courses. Our data come from the administrative systems at Copenhagen Business School and they are merged with survey data on student satisfaction and tutorial participation. Based on simple regression...

  7. TUTORIAL COACHING AS A STRATEGY OF PROFESSIONAL AND PERSONAL DEVELOPMENT: AN EXPERIENCE-BASED STUDY IN A SECONDARY EDUCATION INSTITUTE

    OpenAIRE

    GLADYS IBETH ARIZA ORDÓÑEZ; HÉCTOR BALMES OCAMPO VILLEGAS

    2005-01-01

    Tutorial accompaniment constitutes at present a necessary alternative in the framework of higher education. This workstarts with a general conceptualization of the tutorial, and makes a review of the styles, methods and proceduresrelated to this academic life facet which can effectively contribute to reach the goals the present higher education pursuitwhen it is applied in a coherent and systematic way.Considering the changes that the economy as well as the legislation have generated in educa...

  8. Analysis of ECT Synchronization Performance Based on Different Interpolation Methods

    Directory of Open Access Journals (Sweden)

    Yang Zhixin

    2014-01-01

    Full Text Available There are two synchronization methods of electronic transformer in IEC60044-8 standard: impulsive synchronization and interpolation. When the impulsive synchronization method is inapplicability, the data synchronization of electronic transformer can be realized by using the interpolation method. The typical interpolation methods are piecewise linear interpolation, quadratic interpolation, cubic spline interpolation and so on. In this paper, the influences of piecewise linear interpolation, quadratic interpolation and cubic spline interpolation for the data synchronization of electronic transformer are computed, then the computational complexity, the synchronization precision, the reliability, the application range of different interpolation methods are analyzed and compared, which can serve as guide studies for practical applications.

  9. Multi-beam synchronous measurement based on PSD phase detection using frequency-domain multiplexing

    Science.gov (United States)

    Duan, Ying; Qin, Lan; Xue, Lian; Xi, Feng; Mao, Jiubing

    2013-10-01

    According to the principle of centroid measurement, position-sensitive detectors (PSD) are commonly used for micro displacement detection. However, single-beam detection method cannot satisfy such tasks as multi-dimension position measurement, three dimension vision reconstruction, and robot precision positioning, which require synchronous measurement of multiple light beams. Consequently, we designed PSD phase detection method using frequency-domain multiplexing for synchronous detection of multiple modulated light beams. Compared to previous PSD amplitude detection method, the phase detection method using FDM has advantages of simplified measuring system, low cost, high capability of resistance to light interference as well as improved resolution. The feasibility of multi-beam synchronous measurement based on PSD phase detection using FDM was validated by multi-beam measuring experiments. The maximum non-linearity error of the multi-beam synchronous measurement is 6.62%.

  10. Validation of an Innovative Satellite-Based UV Dosimeter

    Science.gov (United States)

    Morelli, Marco; Masini, Andrea; Simeone, Emilio; Khazova, Marina

    2016-08-01

    We present an innovative satellite-based UV (ultraviolet) radiation dosimeter with a mobile app interface that has been validated by exploiting both ground-based measurements and an in-vivo assessment of the erythemal effects on some volunteers having a controlled exposure to solar radiation.Both validations showed that the satellite-based UV dosimeter has a good accuracy and reliability needed for health-related applications.The app with this satellite-based UV dosimeter also includes other related functionalities such as the provision of safe sun exposure time updated in real-time and end exposure visual/sound alert. This app will be launched on the global market by siHealth Ltd in May 2016 under the name of "HappySun" and available both for Android and for iOS devices (more info on http://www.happysun.co.uk).Extensive R&D activities are on-going for further improvement of the satellite-based UV dosimeter's accuracy.

  11. BOLDSync: a MATLAB-based toolbox for synchronized stimulus presentation in functional MRI.

    Science.gov (United States)

    Joshi, Jitesh; Saharan, Sumiti; Mandal, Pravat K

    2014-02-15

    Precise and synchronized presentation of paradigm stimuli in functional magnetic resonance imaging (fMRI) is central to obtaining accurate information about brain regions involved in a specific task. In this manuscript, we present a new MATLAB-based toolbox, BOLDSync, for synchronized stimulus presentation in fMRI. BOLDSync provides a user friendly platform for design and presentation of visual, audio, as well as multimodal audio-visual (AV) stimuli in functional imaging experiments. We present simulation experiments that demonstrate the millisecond synchronization accuracy of BOLDSync, and also illustrate the functionalities of BOLDSync through application to an AV fMRI study. BOLDSync gains an advantage over other available proprietary and open-source toolboxes by offering a user friendly and accessible interface that affords both precision in stimulus presentation and versatility across various types of stimulus designs and system setups. BOLDSync is a reliable, efficient, and versatile solution for synchronized stimulus presentation in fMRI study. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Symbol Synchronization for SDR Using a Polyphase Filterbank Based on an FPGA

    Directory of Open Access Journals (Sweden)

    P. Fiala

    2015-09-01

    Full Text Available This paper is devoted to the proposal of a highly efficient symbol synchronization subsystem for Software Defined Radio. The proposed feedback phase-locked loop timing synchronizer is suitable for parallel implementation on an FPGA. The polyphase FIR filter simultaneously performs matched-filtering and arbitrary interpolation between acquired samples. Determination of the proper sampling instant is achieved by selecting a suitable polyphase filterbank using a derived index. This index is determined based on the output either the Zero-Crossing or Gardner Timing Error Detector. The paper will extensively focus on simulation of the proposed synchronization system. On the basis of this simulation, a complete, fully pipelined VHDL description model is created. This model is composed of a fully parallel polyphase filterbank based on distributed arithmetic, timing error detector and interpolation control block. Finally, RTL synthesis on an Altera Cyclone IV FPGA is presented and resource utilization in comparison with a conventional model is analyzed.

  13. Coupling Flux Towers and Networks with Proximal and Remote Sensing Data: New Tools to Collect and Share Time-Synchronized Hourly Fluxes

    Science.gov (United States)

    Burba, George; Avenson, Tom; Burkart, Andreas; Gamon, John; Guan, Kaiyu; Julitta, Tommaso; Pastorello, Gilberto; Sakowska, Karolina

    2017-04-01

    optical and flux data in space Current flux towers can be augmented with ground optical sensors and use standard routines to deliver continuous products (e.g. SIF, PRI, NDVI, etc.) based on automated field spectrometers (e.g., FloX and RoX, etc.) and other optical systems Schedule can be developed to point ground optical sensor into the footprint, or to run leaf chamber measurements in the footprint, at the same time with the satellite or UAV above the footprint Full snapshot of the satellite pixel can then be constructed including leaf-level, ground optical sensor, and flux measurements from the same footprint area closely coupled with the satellite measurements to help interpret satellite data, validate models, and improve upscaling Several dozens of new towers already operational globally can be readily adapted for the proposed concept. In addition, over 500 active traditional towers can be updated to synchronize their data with satellite measurements. This presentation will show how FluxSuite system is used by major networks, and describe the concept of how this approach can be utilized to couple satellite and tower data.

  14. Variance based OFDM frame synchronization

    Directory of Open Access Journals (Sweden)

    Z. Fedra

    2012-04-01

    Full Text Available The paper deals with a new frame synchronization scheme for OFDM systems and calculates the complexity of this scheme. The scheme is based on the computing of the detection window variance. The variance is computed in two delayed times, so a modified Early-Late loop is used for the frame position detection. The proposed algorithm deals with different variants of OFDM parameters including guard interval, cyclic prefix, and has good properties regarding the choice of the algorithm's parameters since the parameters may be chosen within a wide range without having a high influence on system performance. The verification of the proposed algorithm functionality has been performed on a development environment using universal software radio peripheral (USRP hardware.

  15. A stable-manifold-based method for chaos control and synchronization

    International Nuclear Information System (INIS)

    Chen Shihua; Zhang Qunjiao; Xie Jin; Wang Changping

    2004-01-01

    A stable-manifold-based method is proposed for chaos control and synchronization. The novelty of this new and effective method lies in that, once the suitable stable manifold according to the desired dynamic properties is constructed, the goal of control is only to force the system state to lie on the selected stable manifold because once the stable manifold is reached, the chaotic system will be guided towards the desired target. The effectiveness of the approach and idea is tested by stabilizing the Newton-Leipnik chaotic system which possesses more than one strange attractor and by synchronizing the unified chaotic system which unifies both the Lorenz system and the Chen system

  16. DSP Based Direct Torque Control of Permanent Magnet Synchronous Motor (PMSM) using Space Vector Modulation (DTC-SVM)

    DEFF Research Database (Denmark)

    Swierczynski, Dariusz; Kazmierkowski, Marian P.; Blaabjerg, Frede

    2002-01-01

    DSP Based Direct Torque Control of Permanent Magnet Synchronous Motor (PMSM) using Space Vector Modulation (DTC-SVM)......DSP Based Direct Torque Control of Permanent Magnet Synchronous Motor (PMSM) using Space Vector Modulation (DTC-SVM)...

  17. A Spatiotemporal-Chaos-Based Cryptosystem Taking Advantage of Both Synchronous and Self-Synchronizing Schemes

    Science.gov (United States)

    Lü, Hua-Ping; Wang, Shi-Hong; Li, Xiao-Wen; Tang, Guo-Ning; Kuang, Jin-Yu; Ye, Wei-Ping; Hu, Gang

    2004-06-01

    Two-dimensional one-way coupled map lattices are used for cryptography where multiple space units produce chaotic outputs in parallel. One of the outputs plays the role of driving for synchronization of the decryption system while the others perform the function of information encoding. With this separation of functions the receiver can establish a self-checking and self-correction mechanism, and enjoys the advantages of both synchronous and self-synchronizing schemes. A comparison between the present system with the system of advanced encryption standard (AES) is presented in the aspect of channel noise influence. Numerical investigations show that our system is much stronger than AES against channel noise perturbations, and thus can be better used for secure communications with large channel noise.

  18. New series of ORACLE tutorials, March-June 2006

    CERN Multimedia

    Catherine Delamare

    2006-01-01

    The IT DES Oracle Support team is pleased to announce the new series of Oracle tutorials with the proposed schedule: Thursday 20 April - SQL I - Eva Dafonte Perez Thursday 27 April - SQL II - Lucia Moreno Lopez Thursday 4 May - Architecture - Montse Collados Thursday 11 May - Tuning - Michal Kwiatek Thursday 1 June - PL/SQL I - Eva Dafonte Perez Thursday 8 June - PL/SQL II - Nilo Segura Thursday 15 June - Oracle Tools and Bindings with languages - Eric Grancher, Nilo Segura These tutorials will take place in the IT Auditorium (bldg. 31/3-004) starting at 10:00. The average duration will be 1 hour plus time for questions. There is no need to register in advance. You can access the previous 2002-2003 sessions at http://it-des.web.cern.ch/IT-DES/DIS/oracle/tutorials.html If you need more information, please contact Catherine.Delamare@cern.ch

  19. Understanding Medical Words: A Tutorial from the National Library of Medicine

    Science.gov (United States)

    ... page: https://medlineplus.gov/medicalwords.html Understanding Medical Words: A Tutorial from the National Library of Medicine ... enable JavaScript. This tutorial teaches you about medical words. You'll learn about how to put together ...

  20. Applications of Geostationary Satellite Data to Aviation

    Science.gov (United States)

    Ellrod, Gary P.; Pryor, Kenneth

    2018-03-01

    Weather is by far the most important factor in air traffic delays in the United States' National Airspace System (NAS) according to the Federal Aviation Administration (FAA). Geostationary satellites have been an effective tool for the monitoring of meteorological conditions that affect aviation operations since the launch of the first Synchronous Meteorological Satellite (SMS) in the United States in 1974. This paper will review the global use of geostationary satellites in support of aviation weather since their inception, with an emphasis on the latest generation of satellites, such as Geostationary Operational Environmental Satellite (GOES)-R (16) with its Advanced Baseline Imager (ABI) and Geostationary Lightning Mapper (GLM). Specific applications discussed in this paper include monitoring of convective storms and their associated hazards, fog and low stratus, turbulence, volcanic hazards, and aircraft icing.

  1. A tutorial on Fisher information

    NARCIS (Netherlands)

    Ly, A.; Marsman, M.; Verhagen, J.; Grasman, R.P.P.P.; Wagenmakers, E.-M.

    2017-01-01

    In many statistical applications that concern mathematical psychologists, the concept of Fisher information plays an important role. In this tutorial we clarify the concept of Fisher information as it manifests itself across three different statistical paradigms. First, in the frequentist paradigm,

  2. Would You Watch It? Creating Effective and Engaging Video Tutorials

    Science.gov (United States)

    Martin, Nichole A.; Martin, Ross

    2015-01-01

    Video tutorials are a common form of library instruction used with distance learners. This paper combines professional experience and literature reviews from multiple disciplines to provide a contextual overview of recommendations and findings for effective and engaging videos. The tools for tutorials appear in five main categories: screencasts,…

  3. Anti-synchronization of chaotic oscillators

    International Nuclear Information System (INIS)

    Kim, Chil-Min; Rim, Sunghwan; Kye, Won-Ho; Ryu, Jung-Wan; Park, Young-Jai

    2003-01-01

    We have observed anti-synchronization phenomena in coupled identical chaotic oscillators. Anti-synchronization can be characterized by the vanishing of the sum of relevant variables. We have qualitatively analyzed its base mechanism by using the dynamics of the difference and the sum of the relevant variables in coupled chaotic oscillators. Near the threshold of the synchronization and anti-synchronization transition, we have obtained the novel characteristic relation

  4. Online interactive tutorials for creating graphs with excel 2007 or 2010.

    Science.gov (United States)

    Vanselow, Nicholas R; Bourret, Jason C

    2012-01-01

    Graphic display of clinical data is a useful tool for the behavior-analytic clinician. However, graphs can sometimes be difficult to create. We describe how to access and use an online interactive tutorial that teaches the user to create a variety of graphs often used by behavior analysts. Three tutorials are provided that cover the basics of Microsoft Excel 2007 or 2010, creating graphs for clinical purposes, and creating graphs for research purposes. The uses for this interactive tutorial and other similar programs are discussed.

  5. You Tube Video Genres. Amateur how-to Videos Versus Professional Tutorials

    Directory of Open Access Journals (Sweden)

    Andreea Mogoș

    2015-12-01

    Full Text Available In spite of the fact that there is a vast literature on traditional textual and visual genre classifications, the categorization of web content is still a difficult task, because this medium is fluid, unstable and fast-paced on one hand and, on the other hand, the genre classifications are socially constructed through the tagging process and the interactions (commenting, rating, chatting. This paper focuses on YouTube tutorials and aims to compare video tutorials produced by professionals with amateur video tutorials.

  6. Subtitled video tutorials, an accessible teaching material

    Directory of Open Access Journals (Sweden)

    Luis Bengochea

    2012-11-01

    Full Text Available The use of short-lived audio-visual tutorials constitutes an educational resource very attractive for young students, widely familiar with this type of format similar to YouTube clips. Considered as "learning pills", these tutorials are intended to strengthen the understanding of complex concepts that because their dynamic nature can’t be represented through texts or diagrams. However, the inclusion of this type of content in eLearning platforms presents accessibility problems for students with visual or hearing disabilities. This paper describes this problem and shows the way in which a teacher could add captions and subtitles to their videos.

  7. Clock synchronization and dispersion

    International Nuclear Information System (INIS)

    Giovannetti, Vittorio; Lloyd, Seth; Maccone, Lorenzo; Wong, Franco N C

    2002-01-01

    We present a method to defeat effects of dispersion of timing signals when synchronizing clocks. It is based on the recently proposed 'conveyor belt synchronization' scheme and on the quantum dispersion cancellation effect

  8. A Space Based Solar Power Satellite System

    Science.gov (United States)

    Engel, J. M.; Polling, D.; Ustamujic, F.; Yaldiz, R.; et al.

    2002-01-01

    (SPoTS) supplying other satellites with energy. SPoTS is due to be commercially viable and operative in 2020. of Technology designed the SPoTS during a full-time design period of six weeks as a third year final project. The team, organized according to the principles of systems engineering, first conducted a literature study on space wireless energy transfer to select the most suitable candidates for use on the SPoTS. After that, several different system concepts have been generated and evaluated, the most promising concept being worked out in greater detail. km altitude. Each SPoTS satellite has a 50m diameter inflatable solar collector that focuses all received sunlight. Then, the received sunlight is further redirected by means of four pointing mirrors toward four individual customer satellites. A market-analysis study showed, that providing power to geo-stationary communication satellites during their eclipse would be most beneficial. At arrival at geo-stationary orbit, the focused beam has expended to such an extent that its density equals one solar flux. This means that customer satellites can continue to use their regular solar arrays during their eclipse for power generation, resulting in a satellite battery mass reduction. the customer satellites in geo-stationary orbit, the transmitted energy beams needs to be pointed with very high accuracy. Computations showed that for this degree of accuracy, sensors are needed, which are not mainstream nowadays. Therefore further research must be conducted in this area in order to make these high-accuracy-pointing systems commercially attractive for use on the SPoTS satellites around 2020. Total 20-year system lifetime cost for 18 SPoT satellites are estimated at approximately USD 6 billion [FY2001]. In order to compete with traditional battery-based satellite power systems or possible ground based wireless power transfer systems the price per kWh for the customer must be significantly lower than the present one

  9. A Framework for Synchronous Web-Based Professional Development: Measuring the Impact of Webinar Instruction

    Science.gov (United States)

    Rich, Rachel L.

    2011-01-01

    Through the evolution and proliferation of the Internet, distance and online education have become more prevalent in modern society. Synchronous web-based professional development continues to gain popularity. Although online education has grown in popularity and breadth, there has been a lack of research about the impact of synchronous web-based…

  10. Simulation of Processes in Dual Three-Phase System on the Base of Four Inverters with Synchronized Modulation

    OpenAIRE

    Oleschuk, Valentin; Grandi, Gabriele; Sanjeevikumar, Padmanaban

    2011-01-01

    Novel method of space-vector-based pulse-width modulation (PWM) has been disseminated for synchronous control of four inverters feeding six-phase drive on the base of asymmetrical induction motor which has two sets of windings spatially shifted by 30 electrical degrees. Basic schemes of synchronized PWM, applied for control of four separate voltage-source inverters, allow both continuous phase voltages synchronization in the system and required power sharing between DC sources. Detailed MATLA...

  11. Supporting motivation, task performance and retention in video tutorials for software training

    NARCIS (Netherlands)

    van der Meij, Hans; van der Meij, Jan; Voerman, Tessa; Duipmans, Evert

    2017-01-01

    Video tutorials for software training are becoming more and more popular, but their construction and effectiveness is understudied. This paper presents a theoretical model that combines demonstration-based training (DBT) and multimedia learning theory as a framework for design. The study

  12. Plasma waves and electric discharges induced by a beam from a high-latitude satellite

    International Nuclear Information System (INIS)

    Kuns, G.; Koen, G.

    1985-01-01

    Using P78-2 satellite measurements of characteristics of space probe charging in synchronous orbit are carried out. A particle beam generation system including electron and ion guns was part of the satellite equipment. Electric charge analyser placed aboard the satellite in course of electron and ion beam generation recorded plasma waves and electric discharges

  13. Modular approach for satellite communication ground terminals

    Science.gov (United States)

    Gould, G. R.

    1984-01-01

    The trend in satellite communications is toward completely digital, time division multiple access (TDMA) systems with uplink and downlink data rates dictated by the type of service offered. Trunking terminals will operate in the 550 MBPS (megabit per second) region uplink and downlink, whereas customer premise service (CPS) terminals will operate in the 25 to 10 MBPS region uplink and in the 200 MBPS region downlink. Additional criteria for the ground terminals will be to maintain clock sychronization with the system and burst time integrity to within a matter of nanoseconds, to process required order-fire information, to provide adaptive data scrambing, and to compensate for variations in the user input output data rates, and for changes in range in the satellite communications links resulting from satellite perturbations in orbit. To achieve the required adaptability of a ground terminal to the above mentioned variables, programmable building blocks can be developed that will meet all of these requirements. To maintain system synchronization, i.e., all bursted data arriving at the satellite within assigned TDMA windows, ground terminal transmit data rates and burst timing must be maintained within tight tolerances. With a programmable synchronizer as the heart of the terminal timing generation, variable data rates and burst timing tolerances are achievable. In essence, the unit inputs microprocessor generated timing words and outputs discrete timing pulses.

  14. Breaking projective chaos synchronization secure communication using filtering and generalized synchronization

    International Nuclear Information System (INIS)

    Alvarez, G.; Li Shujun; Montoya, F.; Pastor, G.; Romera, M.

    2005-01-01

    This paper describes the security weaknesses of a recently proposed secure communication method based on chaotic masking using projective synchronization of two chaotic systems. We show that the system is insecure and how to break it in two different ways, by high-pass filtering and by generalized synchronization

  15. A tutorial review of functional connectivity analysis methods and their interpretational pitfalls

    Directory of Open Access Journals (Sweden)

    Andre M Bastos

    2016-01-01

    Full Text Available Oscillatory neuronal activity may provide a mechanism for dynamic network coordination. Rhythmic neuronal interactions can be quantified using multiple metrics, each with their own advantages and disadvantages. This tutorial will review and summarize current analysis methods used in the field of invasive and non-invasive electrophysiology to study the dynamic connections between neuronal populations. First, we review metrics for functional connectivity, including coherence, phase synchronization, phase-slope index, and Granger causality, with the specific aim to provide an intuition for how these metrics work, as well as their quantitative definition. Next, we highlight a number of interpretational caveats and common pitfalls that can arise when performing functional connectivity analysis, including the common reference problem, the signal to noise ratio problem, the volume conduction problem, the common input problem, and the trial sample size bias problem. These pitfalls will be illustrated by presenting a set of MATLAB-scripts, which can be executed by the reader to simulate each of these potential problems. We discuss of how these issues can be addressed using current methods.

  16. Satellite-borne study of seismic phenomena by low frequency magnetic field observations

    Science.gov (United States)

    Schwingenschuh, Konrad; Magnes, Werner; Xuhui, Shen; Wang, Jindong; Pollinger, Andreas; Hagen, Christian; Prattes, Gustav; Eichelberger, Hans-Ulrich; Wolbang, Daniel; Boudjada, Mohammed Y.; Besser, Bruno P.; Rozhnoi, Alexander A.; Zhang, Tielong

    2015-04-01

    A combined scalar-vector magnetic field experiment will be flown on the upcoming CSES mission (China Seismo-Electromagnetic Satellite). Magnetic field data from DC to 30 Hz will be measured with an accuracy of about 10 pT. A fluxgate instrument will provide the 3 magnetic field components and a new type of an optically pumped magnetometer [see Pollinger, 2010] will measure the magnitude of the ambient magnetic field. The satellite will operate in a Sun synchronous polar orbit at an altitude of about 500 km and with an inclination of 97°. We present a model of magnetic field fluctuations in the upper ionosphere based on previous satellite observations and on a model of the lithospheric-atmospheric-ionospheric coupling. Pollinger et al., CDSM-a new scalar magnetometer, EGU General Assembly 2010

  17. New series of ORACLE tutorials, March-June 2006

    CERN Multimedia

    Catherine Delamare

    2006-01-01

    The IT DES Oracle Support team is pleased to announce the new series of Oracle tutorials with the proposed schedule: Thursday 30 March - Design - Arash Khodabandeh Thursday 20 April - SQL I - Eva Dafonte Perez Thursday 27 April - SQL II - Lucia Moreno Lopez Thursday 4 May - Architecture - Montse Collados Thursday 11 May - Tuning - Michal Kwiatek Thursday 1 June - PL/SQL I - Eva Dafonte Perez Thursday 8 June - PL/SQL II - Nilo Segura Thursday 15 June - Oracle Tools and Bindings with languages - Eric Grancher, Nilo Segura These tutorials will take place in the IT Auditorium (bldg. 31/3-004) starting at 10:00. The average duration will be 1 hour plus time for questions. There is no need to register in advance. You can access the previous 2002-2003 sessions at http://it-des.web.cern.ch/IT-DES/DIS/oracle/tutorials.html If you need more information, please contact Catherine.Delamare@cern.ch

  18. Satellite-based Flood Modeling Using TRMM-based Rainfall Products

    Directory of Open Access Journals (Sweden)

    Greg Easson

    2007-12-01

    Full Text Available Increasingly available and a virtually uninterrupted supply of satellite-estimatedrainfall data is gradually becoming a cost-effective source of input for flood predictionunder a variety of circumstances. However, most real-time and quasi-global satelliterainfall products are currently available at spatial scales ranging from 0.25o to 0.50o andhence, are considered somewhat coarse for dynamic hydrologic modeling of basin-scaleflood events. This study assesses the question: what are the hydrologic implications ofuncertainty of satellite rainfall data at the coarse scale? We investigated this question onthe 970 km2 Upper Cumberland river basin of Kentucky. The satellite rainfall productassessed was NASA’s Tropical Rainfall Measuring Mission (TRMM Multi-satellitePrecipitation Analysis (TMPA product called 3B41RT that is available in pseudo real timewith a latency of 6-10 hours. We observed that bias adjustment of satellite rainfall data canimprove application in flood prediction to some extent with the trade-off of more falsealarms in peak flow. However, a more rational and regime-based adjustment procedureneeds to be identified before the use of satellite data can be institutionalized among floodmodelers.

  19. Leo satellite-based telecommunication network concepts

    Science.gov (United States)

    Aiken, John G.; Swan, Peter A.; Leopold, Ray J.

    1991-01-01

    Design considerations are discussed for Low Earth Orbit (LEO) satellite based telecommunications networks. The satellites are assumed to be connected to each other via intersatellite links. They are connected to the end user either directly or through gateways to other networks. Frequency reuse, circuit switching, packet switching, call handoff, and routing for these systems are discussed by analogy with terrestrial cellular (mobile radio) telecommunication systems.

  20. Simultaneously precise frequency transfer and time synchronization using feed-forward compensation technique via 120 km fiber link.

    Science.gov (United States)

    Chen, Xing; Lu, Jinlong; Cui, Yifan; Zhang, Jian; Lu, Xing; Tian, Xusheng; Ci, Cheng; Liu, Bo; Wu, Hong; Tang, Tingsong; Shi, Kebin; Zhang, Zhigang

    2015-12-22

    Precision time synchronization between two remote sites is desired in many applications such as global positioning satellite systems, long-baseline interferometry, coherent radar detection and fundamental physics constant measurements. The recently developed frequency dissemination technologies based on optical fiber link have improved the transfer instability to the level of 10(-19)/day at remote location. Therefore it is possible to keep clock oscillation at remote locations continuously corrected, or to reproduce a "virtual" clock on the remote location. However the initial alignment and the correction of 1 pps timing signal from time to time are still required, besides the highly stabilized clock frequency transfer between distant locations. Here we demonstrate a time synchronization based on an ultra-stable frequency transfer system via 120-km commercial fiber link by transferring an optical frequency comb. Both the phase noise compensation in frequency dissemination and temporal basis alignment in time synchronization were implemented by a feed-forward digital compensation (FFDC) technique. The fractional frequency instability was measured to be 6.18 × 10(-20) at 2000 s. The timing deviation of time synchronization was measured to be 0.6 ps in 1500 s. This technique also can be applied in multi-node fiber network topology.

  1. Fine-tuning satellite-based rainfall estimates

    Science.gov (United States)

    Harsa, Hastuadi; Buono, Agus; Hidayat, Rahmat; Achyar, Jaumil; Noviati, Sri; Kurniawan, Roni; Praja, Alfan S.

    2018-05-01

    Rainfall datasets are available from various sources, including satellite estimates and ground observation. The locations of ground observation scatter sparsely. Therefore, the use of satellite estimates is advantageous, because satellite estimates can provide data on places where the ground observations do not present. However, in general, the satellite estimates data contain bias, since they are product of algorithms that transform the sensors response into rainfall values. Another cause may come from the number of ground observations used by the algorithms as the reference in determining the rainfall values. This paper describe the application of bias correction method to modify the satellite-based dataset by adding a number of ground observation locations that have not been used before by the algorithm. The bias correction was performed by utilizing Quantile Mapping procedure between ground observation data and satellite estimates data. Since Quantile Mapping required mean and standard deviation of both the reference and the being-corrected data, thus the Inverse Distance Weighting scheme was applied beforehand to the mean and standard deviation of the observation data in order to provide a spatial composition of them, which were originally scattered. Therefore, it was possible to provide a reference data point at the same location with that of the satellite estimates. The results show that the new dataset have statistically better representation of the rainfall values recorded by the ground observation than the previous dataset.

  2. Infrared Astronomy Satellite

    Science.gov (United States)

    Ferrera, G. A.

    1981-09-01

    In 1982, the Infrared Astronomy Satellite (IRAS) will be launched into a 900-km sun-synchronous (twilight) orbit to perform an unbiased, all-sky survey of the far-infrared spectrum from 8 to 120 microns. Observations telemetered to ground stations will be compiled into an IR astronomy catalog. Attention is given the cryogenically cooled, 60-cm Ritchey-Chretien telescope carried by the satellite, whose primary and secondary mirrors are fabricated from beryllium by means of 'Cryo-Null Figuring'. This technique anticipates the mirror distortions that will result from cryogenic cooling of the telescope and introduces dimensional compensations for them during machining and polishing. Consideration is also given to the interferometric characterization of telescope performance and Cryo/Thermal/Vacuum simulated space environment testing.

  3. Assessing the impact of a tutorial intervention when teaching the ray model of light in introductory physics

    International Nuclear Information System (INIS)

    Kesonen, M H P; Asikainen, M A; Hirvonen, P E

    2013-01-01

    This paper presents a 90 min tutorial intervention which permits the use of the Tutorials in Introductory Physics curriculum in a conventional physics course. In addition, the paper describes the impact of the intervention on students' understanding of the ray model of light in the context of geometrical images. In 2011 and 2012 a total of 79 introductory students participated in the intervention, where they worked with the Light and Shadow tutorial after having received lecture-based instruction in a conventional physics course. The impact of the intervention on the students' learning was assessed by means of paper-and-pencil test questions at the beginning and end of the intervention. The results showed that the proportion of correct or nearly correct answers increased by 17 percentage points during the intervention. Thus, it can be claimed that the intervention was a useful supplement to a conventional physics course by helping students to improve their understanding of the ray model of light. In addition, the intervention may serve as an intermediate step towards adopting the tutorials, since it permits the curriculum of a conventional physics course to be tested without large changes being made to the course. This type of information is needed in support of institutional changes towards more research-based instructional practices. (paper)

  4. Synchronization of delay-coupled nonlinear oscillators : an approach based on the stability analysis of synchronized equilibria

    NARCIS (Netherlands)

    Michiels, W.; Nijmeijer, H.

    2009-01-01

    We consider the synchronization problem of an arbitrary number of coupled nonlinear oscillators with delays in the interconnections. The network topology is described by a directed graph. Unlike the conventional approach of deriving directly sufficient synchronization conditions, the approach of the

  5. Stability of a dual-spin satellite with two dampers

    Science.gov (United States)

    Alfriend, K. T.; Hubert, C. H.

    1974-01-01

    The rotational stability of a dual-spin satellite consisting of a main body and a symmetric rotor, both spinning about a common axis, is investigated. The main body is equipped with a spring-mass damper, while a partially filled viscous ring damper is mounted on the rapidly spinning rotor. The effect of fluid motion on the rotational stability of the satellite is calculated, considering the fluid as a single particle moving in a tube with viscous damping. Time constants are obtained by solving approximate equations of motion for the nutation-synchronous and the spin-synchronous modes, and the results are found to agree well with the numerical integrations of the exact equations. A limit cycle may exist for some configurations; the nutation angle tends to increase in such cases.

  6. Mobile satellite business networks: A part of the European mobile system

    Science.gov (United States)

    deMateo, M. L.; Jongejans, A.; Loisy, C.; VanHimbeeck, C.; Marchal, J. P.; Borella, A.; Sartori, M.

    1995-01-01

    The European Space Agency (ESA) is presently procuring an L-band payload EMS, to be embarked on the ITALSAT-2 satellite due for launch in early 1996, in order to promote a regional European mobile system. One of the Land Mobile Communication systems supported by EMS is the MSBN (Mobile Satellite Business Network) voice and data system which will offer the services of a business network on a seamless European coverage. This paper will first recall the characteristics of the MSBN system, which is based on quasi-synchronized CDMA (Code Division Multiple Access) techniques in both directions, and then describe the CDMA receivers implementation. Main validation test results will also be reported confirming predicted performances.

  7. Mission studies on constellation of LEO satellites with remote-sensing and communication payloads

    Science.gov (United States)

    Chen, Chia-Ray; Hwang, Feng-Tai; Hsueh, Chuang-Wei

    2017-09-01

    Revisiting time and global coverage are two major requirements for most of the remote sensing satellites. Constellation of satellites can get the benefit of short revisit time and global coverage. Typically, remote sensing satellites prefer to choose Sun Synchronous Orbit (SSO) because of fixed revisiting time and Sun beta angle. The system design and mission operation will be simple and straightforward. However, if we focus on providing remote sensing and store-and-forward communication services for low latitude countries, Sun Synchronous Orbit will not be the best choice because we need more satellites to cover the communication service gap in low latitude region. Sometimes the design drivers for remote sensing payloads are conflicted with the communication payloads. For example, lower orbit altitude is better for remote sensing payload performance, but the communication service zone will be smaller and we need more satellites to provide all time communication service. The current studies focus on how to provide remote sensing and communication services for low latitude countries. A cost effective approach for the mission, i.e. constellation of microsatellites, will be evaluated in this paper.

  8. Tutorial on architectural acoustics

    Science.gov (United States)

    Shaw, Neil; Talaske, Rick; Bistafa, Sylvio

    2002-11-01

    This tutorial is intended to provide an overview of current knowledge and practice in architectural acoustics. Topics covered will include basic concepts and history, acoustics of small rooms (small rooms for speech such as classrooms and meeting rooms, music studios, small critical listening spaces such as home theatres) and the acoustics of large rooms (larger assembly halls, auditoria, and performance halls).

  9. Exploiting Schemas in Data Synchronization

    DEFF Research Database (Denmark)

    Foster, J. Nathan; Greenwald, Michael B.; Kirkegaard, Christian

    2005-01-01

    Increased reliance on optimistic data replication has led to burgeoning interest in tools and frameworks for disconnected updates to replicated data.We have implemented a generic synchronization framework, called HARMONY, that can be used to build state-based synchronizers for a wide variety...... of tree-structureddata formats. A novel feature of this framework is that the synchronization process - in particular, the recognition of conflicts - is driven by the schema of the structures being synchronized.We formalize HARMONY's synchronization algorithm, state a simple and intuitive specification......, and illustrate, using simple address books as a case study, how it can be used to synchronize trees representing a variety of specific forms of applicationdata, including sets, records, tuples, and relations....

  10. Tutorial Video Series: Using Stakeholder Outreach to Increase ...

    Science.gov (United States)

    The limited amount of toxicity data on thousands of chemicals found in consumer products has led to the development of research endeavors such as the U.S. EPA’s Toxicity Forecaster (ToxCast). ToxCast uses high-throughput screening technology to evaluate thousands of chemicals for potential toxicity. At the end of 2013, U.S. EPA released ToxCast chemical data on almost 2,000 chemicals through the interactive Chemical Safety for Sustainability (iCSS) Dashboard. The iCSS Dashboard provides public access to the high-throughput screening data that can be used to inform the evaluation of the safety of chemicals. U.S. EPA recognized early in the development of ToxCast that stakeholder outreach was needed in order to translate the complex scientific information featured in the iCSS Dashboard and data, with the goal of educating the diverse user community through targeted efforts to increase data usage and analysis. Through survey feedback and the request of stakeholders, a series of tutorial videos to demonstrate how to access and use the data has been planned, and the first video of the series has been released to guide data usage. This presentation will describe the video tutorial strategy including an overview of: 1) Stakeholder outreach goals and approach; 2) Planning, production, and dissemination of tutorial videos; 3) Overview of Survey Feedback; 4) Overview of tutorial video usage statistics and usage of the ToxCast data. This stakeholder-outreach approach

  11. Communicating Big Data with the Public via Tutorials

    Science.gov (United States)

    Montgomery, Michele

    2015-08-01

    Although numerical models that researchers use to analyze large astronomy data sets may be easily found on NASA websites, tutorials on how to use these models and understanding the products of the models are lacking. Thus, communication with the public is ineffective. Where the public could easily engage with data and models to determine if their work and lives could be impacted, and if so, to plan accordingly, a lack of good tutorials typically results in the public waiting for a tweet, a post on Facebook, an announcement on a NASA webpage, an alert sent via text message or email, etc. An example is a solar flare or coronal mass ejection event that may impact GPS devices, the precision of which is heavily relied upon by several sectors of the public and military. To allow the public to engage in real time with solar data and NASA developed heliophysics software, we have developed tutorials. In this work, we present our tutorials made for NASA's Living With a Star Program on the such as Integrated Space Weather Analysis (ISWA) layout and the WSA-ENLIL-CONE Model to analyze a CME Evolution that occurred in 2010. We present our results and our analysis of the public's ability to understand the model's predictions of whether the event will impact Earth. By training the public to use the data and to understand model predictions, we turn passive recipients into engaged and self-supporting users of NASA data of space weather events.

  12. Engaging undergraduate nursing students in face-to-face tutorials.

    Science.gov (United States)

    Elder, Ruth L; Lewis, Peter A; Windsor, Carol A; Wheeler, Margaret; Forster, Elizabeth; Foster, Joanne; Chapman, Helen

    2011-09-01

    Chronic nursing shortages have placed increasing pressure on many nursing schools to recruit greater numbers of students with the consequence of larger class sizes. Larger class sizes have the potential to lead to student disengagement. This paper describes a case study that examined the strategies used by a group of nursing lecturers to engage students and to overcome passivity in a Bachelor of Nursing programme. A non-participant observer attended 20 tutorials to observe five academics deliver four tutorials each. Academics were interviewed both individually and as a group following the completion of all tutorial observations. All observations, field notes, interviews and focus groups were coded separately and major themes identified. From this analysis two broad categories emerged: getting students involved; and engagement as a struggle. Academics used a wide variety of techniques to interest and involve students. Additionally, academics desired an equal relationship with students. They believed that both they and the students had some power to influence the dynamics of tutorials and that neither party had ultimate power. The findings of this study serve to re-emphasise past literature which suggests that to engage students, the academics must also engage. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Studying Interaction in Undergraduate Tutorials: Results from a Small-Scale Evaluation

    Science.gov (United States)

    Shaw, Lorraine; Carey, Phil; Mair, Michael

    2008-01-01

    This article reports on an observation-based evaluation of student-tutor interaction in first-year undergraduate tutorials. Using a single case analysis, the paper looks at how tutors and students built and maintained relationships through two different though interlinked forms of interaction--storytelling and the use of classroom space for…

  14. Finite-time stability and synchronization of memristor-based fractional-order fuzzy cellular neural networks

    Science.gov (United States)

    Zheng, Mingwen; Li, Lixiang; Peng, Haipeng; Xiao, Jinghua; Yang, Yixian; Zhang, Yanping; Zhao, Hui

    2018-06-01

    This paper mainly studies the finite-time stability and synchronization problems of memristor-based fractional-order fuzzy cellular neural network (MFFCNN). Firstly, we discuss the existence and uniqueness of the Filippov solution of the MFFCNN according to the Banach fixed point theorem and give a sufficient condition for the existence and uniqueness of the solution. Secondly, a sufficient condition to ensure the finite-time stability of the MFFCNN is obtained based on the definition of finite-time stability of the MFFCNN and Gronwall-Bellman inequality. Thirdly, by designing a simple linear feedback controller, the finite-time synchronization criterion for drive-response MFFCNN systems is derived according to the definition of finite-time synchronization. These sufficient conditions are easy to verify. Finally, two examples are given to show the effectiveness of the proposed results.

  15. Novel Blind Recognition Algorithm of Frame Synchronization Words Based on Soft-Decision in Digital Communication Systems.

    Science.gov (United States)

    Qin, Jiangyi; Huang, Zhiping; Liu, Chunwu; Su, Shaojing; Zhou, Jing

    2015-01-01

    A novel blind recognition algorithm of frame synchronization words is proposed to recognize the frame synchronization words parameters in digital communication systems. In this paper, a blind recognition method of frame synchronization words based on the hard-decision is deduced in detail. And the standards of parameter recognition are given. Comparing with the blind recognition based on the hard-decision, utilizing the soft-decision can improve the accuracy of blind recognition. Therefore, combining with the characteristics of Quadrature Phase Shift Keying (QPSK) signal, an improved blind recognition algorithm based on the soft-decision is proposed. Meanwhile, the improved algorithm can be extended to other signal modulation forms. Then, the complete blind recognition steps of the hard-decision algorithm and the soft-decision algorithm are given in detail. Finally, the simulation results show that both the hard-decision algorithm and the soft-decision algorithm can recognize the parameters of frame synchronization words blindly. What's more, the improved algorithm can enhance the accuracy of blind recognition obviously.

  16. Synchronized femtosecond laser pulse switching system based nano-patterning technology

    Science.gov (United States)

    Sohn, Ik-Bu; Choi, Hun-Kook; Yoo, Dongyoon; Noh, Young-Chul; Sung, Jae-Hee; Lee, Seong-Ku; Ahsan, Md. Shamim; Lee, Ho

    2017-07-01

    This paper demonstrates the design and development of a synchronized femtosecond laser pulse switching system and its applications in nano-patterning of transparent materials. Due to synchronization, we are able to control the location of each irradiated laser pulse in any kind of substrate. The control over the scanning speed and scanning step of the laser beam enables us to pattern periodic micro/nano-metric holes, voids, and/or lines in various materials. Using the synchronized laser system, we pattern synchronized nano-holes on the surface of and inside various transparent materials including fused silica glass and polymethyl methacrylate to replicate any image or pattern on the surface of or inside (transparent) materials. We also investigate the application areas of the proposed synchronized femtosecond laser pulse switching system in a diverse field of science and technology, especially in optical memory, color marking, and synchronized micro/nano-scale patterning of materials.

  17. Synchronization of vortex-based spin torque nano-oscillators by magnetostatic coupling

    Energy Technology Data Exchange (ETDEWEB)

    Zaspel, C.E., E-mail: craig.zaspel@umwestern.edu

    2015-12-15

    Synchronization of two nanopillar oscillators driven by spin torque and coupled through the magnetic dipolar interaction. The dominant mode in each oscillator is gyrotropic motion of the vortex core in an elliptical orbit about the free layer disk center. The dynamic properties of this mode is investigated by solution the coupled Thiele equations with both nanopillar oscillators having identical dimensions, but with a current mismatch. It is noticed that there is a range in the current difference where the oscillators will be synchronized where the vortex gyrotropic motion will be frequency-locked with the radii of gyrotropic motion equal for both disks. There is, however, a phase shift between the gyrotropic motion with the smaller current disk lagging the higher current disk by a few degrees. - Highlights: • Vortex-based nanopillar oscillators re synchronized by the dipolar interaction. • There is a range of frequencies where both oscillators will frequency-locked. • There are upper and lower critical currents defining a locking range.

  18. Design of Tokamak synchronous data acquisition system based on PXI express

    International Nuclear Information System (INIS)

    Liu Rui; Zheng Wei; Zhang Ming; Weng Chuqiao; Zhuang Ge; Ding Tonghai; Yu Kexun

    2014-01-01

    With the development of J-TEXT device, the original data acquisition system can't meet the experiment's requirement on stability, modularity and sampling rate, so a new data acquisition system needs to be built. This paper introduces the design and implementation of the distributed Tokamak synchronous high-speed data acquisition system based on PXI Express. The acquisition unit consists of PXIe case Nl PXIe 1062Q, PXIe controller NI PXIe-8133 and high-speed synchronous data acquisition card Nl PXIe-6368, compatible with the latest standard of ITER CODAC, so it has good mechanical sealing, strong modularity and high sampling rate etc. The system takes a synchronous difference acquisition for diagnosis signal. The data storage adopts MDSplus which is the general database in the nuclear fusion field. The test and experimental results show that the system can work continuously and stably at 2 MSps sampling rate, and meet the requirement of experiment device's operation well. (authors)

  19. "ASTRO 101" Course Materials 2.0: Next Generation Lecture Tutorials and Beyond

    Science.gov (United States)

    Slater, Stephanie; Grazier, Kevin

    2015-01-01

    Early efforts to create course materials were often local in scale and were based on "gut instinct," and classroom experience and observation. While subsequent efforts were often based on those same instincts and observations of classrooms, they also incorporated the results of many years of education research. These "second generation" course materials, such as lecture tutorials, relied heavily on research indicating that instructors need to actively engage students in the learning process. While imperfect, these curricular innovations, have provided evidence that research-based materials can be constructed, can easily be disseminated to a broad audience, and can provide measureable improvement in student learning across many settings. In order to improve upon this prior work, next generation materials must build upon the strengths of these innovations while engineering in findings from education research, cognitive science, and instructor feedback. A next wave of materials, including a set of next generation lecture tutorials, have been constructed with attention to the body of research on student motivation, and cognitive load; and they are responsive to our body of knowledge on learning difficulties related to specific content in the domain. From instructor feedback, these materials have been constructed to have broader coverage of the materials typically taught in an ASTRO 101 course, to take less class time, and to be more affordable for students. This next generation of lecture tutorials may serve as a template of the ways in which course materials can be reengineered to respond to current instructor and student needs.

  20. Wavelets a tutorial in theory and applications

    CERN Document Server

    1992-01-01

    Wavelets: A Tutorial in Theory and Applications is the second volume in the new series WAVELET ANALYSIS AND ITS APPLICATIONS. As a companion to the first volume in this series, this volume covers several of the most important areas in wavelets, ranging from the development of the basic theory such as construction and analysis of wavelet bases to an introduction of some of the key applications, including Mallat's local wavelet maxima technique in second generation image coding. A fairly extensive bibliography is also included in this volume.Key Features* Covers several of the

  1. Application of Synchronous Text-Based Dialogue Systems in Mental Health Interventions: Systematic Review

    Science.gov (United States)

    Milne, David N

    2017-01-01

    Background Synchronous written conversations (or “chats”) are becoming increasingly popular as Web-based mental health interventions. Therefore, it is of utmost importance to evaluate and summarize the quality of these interventions. Objective The aim of this study was to review the current evidence for the feasibility and effectiveness of online one-on-one mental health interventions that use text-based synchronous chat. Methods A systematic search was conducted of the databases relevant to this area of research (Medical Literature Analysis and Retrieval System Online [MEDLINE], PsycINFO, Central, Scopus, EMBASE, Web of Science, IEEE, and ACM). There were no specific selection criteria relating to the participant group. Studies were included if they reported interventions with individual text-based synchronous conversations (ie, chat or text messaging) and a psychological outcome measure. Results A total of 24 articles were included in this review. Interventions included a wide range of mental health targets (eg, anxiety, distress, depression, eating disorders, and addiction) and intervention design. Overall, compared with the waitlist (WL) condition, studies showed significant and sustained improvements in mental health outcomes following synchronous text-based intervention, and post treatment improvement equivalent but not superior to treatment as usual (TAU) (eg, face-to-face and telephone counseling). Conclusions Feasibility studies indicate substantial innovation in this area of mental health intervention with studies utilizing trained volunteers and chatbot technologies to deliver interventions. While studies of efficacy show positive post-intervention gains, further research is needed to determine whether time requirements for this mode of intervention are feasible in clinical practice. PMID:28784594

  2. [Current state of training in pharmacy education using a problem-based learning/tutorial model with simulated patients and standardized patients at National University Corporation].

    Science.gov (United States)

    Irie, Tetsumi; Nitta, Atsumi; Akaike, Akinori

    2012-01-01

    Simulated/standardized patient-based (SP) education and problem-based learning (PBL) tutorial education become a powerful tool to heighten the pharmacy students' will to learn in order to cultivate the responsibility to contribute to public health and welfare as a clinical professional and to facilitate students' competences to solve problems by themselves. What this program is trying to do is: 1) to establish the system to train, educate and supply SP who are effective in the training and education of pharmacy students in close cooperation with the medical schools and their affiliated hospitals; 2) to improve the quality of the current PBL tutorial education and thereby establish it as an advanced education program in the education of senior students. We carried out the questionnaire to National University Corporation which establishes a school of pharmacy, as to the training and education of SP. The analysis of the answers to the questionnaire revealed the present status of SP in the Pharmaceutical Objective Structured Clinical Examination (OSCE) in the Pharmaceutical Common Achievement Test, and the existence of the problems on how to standardize SP as well as how to cover such expenses. Furthermore, the activity of the first year consisted of the exchange and sharing of information regarding the existing method of training and education of SP and PBL tutorial education and the identification of the problems to be solved in order to improve the quality of the educational program.

  3. A tutorial on the principles of harmonic intonation for trombonists

    Science.gov (United States)

    Keener, Michael Kenneth

    A Tutorial on the Principles of Harmonic Intonation for Trombonists includes a manual containing background information, explanations of the principles of harmonic intonation, and printed musical examples for use in learning and practicing the concepts of harmonic intonation. An audio compact disk containing music files corresponding to the printed music completes the set. This tutorial is designed to allow performing musicians and students to practice intonation skills with the pitch-controlled music on the compact disc. The music on the CD was recorded in movable-comma just intonation, replicating performance parameters of wind, string, and vocal ensembles. The compact disc includes sixty tracks of ear-training exercises and interval studies with which to practice intonation perception and adjustment. Tuning notes and examples of equal-tempered intervals and just intervals are included on the CD. The intonation exercises consist of musical major scales, duets, trios, and quartet phrases to be referenced while playing the printed music. The CD tracks allow the performer to play scales in unison (or practice other harmonic intervals) or the missing part of the corresponding duet, trio, or quartet exercise. Instructions in the manual guide the user through a process that can help prepare musicians for more accurate musical ensemble performance. The contextual essay that accompanies the tutorial includes a description of the tutorial, a review of related literature, methodology of construction of the tutorial, evaluations and outcomes, conclusions and recommendations for further research, and a selected bibliography.

  4. A Tutorial Design Process Applied to an Introductory Materials Engineering Course

    Science.gov (United States)

    Rosenblatt, Rebecca; Heckler, Andrew F.; Flores, Katharine

    2013-01-01

    We apply a "tutorial design process", which has proven to be successful for a number of physics topics, to design curricular materials or "tutorials" aimed at improving student understanding of important concepts in a university-level introductory materials science and engineering course. The process involves the identification…

  5. A time and frequency synchronization method for CO-OFDM based on CMA equalizers

    Science.gov (United States)

    Ren, Kaixuan; Li, Xiang; Huang, Tianye; Cheng, Zhuo; Chen, Bingwei; Wu, Xu; Fu, Songnian; Ping, Perry Shum

    2018-06-01

    In this paper, an efficient time and frequency synchronization method based on a new training symbol structure is proposed for polarization division multiplexing (PDM) coherent optical orthogonal frequency division multiplexing (CO-OFDM) systems. The coarse timing synchronization is achieved by exploiting the correlation property of the first training symbol, and the fine timing synchronization is accomplished by using the time-domain symmetric conjugate of the second training symbol. Furthermore, based on these training symbols, a constant modulus algorithm (CMA) is proposed for carrier frequency offset (CFO) estimation. Theoretical analysis and simulation results indicate that the algorithm has the advantages of robustness to poor optical signal-to-noise ratio (OSNR) and chromatic dispersion (CD). The frequency offset estimation range can achieve [ -Nsc/2 ΔfN , + Nsc/2 ΔfN ] GHz with the mean normalized estimation error below 12 × 10-3 even under the condition of OSNR as low as 10 dB.

  6. Generalized synchronization-based multiparameter estimation in modulated time-delayed systems

    Science.gov (United States)

    Ghosh, Dibakar; Bhattacharyya, Bidyut K.

    2011-09-01

    We propose a nonlinear active observer based generalized synchronization scheme for multiparameter estimation in time-delayed systems with periodic time delay. A sufficient condition for parameter estimation is derived using Krasovskii-Lyapunov theory. The suggested tool proves to be globally and asymptotically stable by means of Krasovskii-Lyapunov method. With this effective method, parameter identification and generalized synchronization of modulated time-delayed systems with all the system parameters unknown, can be achieved simultaneously. We restrict our study for multiple parameter estimation in modulated time-delayed systems with single state variable only. Theoretical proof and numerical simulation demonstrate the effectiveness and feasibility of the proposed technique. The block diagram of electronic circuit for multiple time delay system shows that the method is easily applicable in practical communication problems.

  7. Synchronization in reduced-order of chaotic systems via control approaches based on high-order sliding-mode observer

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, A. [Electrical Engineering Doctoral Program, Mechanical and Electrical Engineering Faculty, Autonomous University of Nuevo Leon, 66450 San Nicolas de los Garza, N.L. (Mexico)], E-mail: angelrdz@gmail.com; De Leon, J. [Electrical Engineering Doctoral Program, Mechanical and Electrical Engineering Faculty, Autonomous University of Nuevo Leon, 66450 San Nicolas de los Garza, N.L. (Mexico)], E-mail: drjleon@gmail.com; Fridman, L. [Department of Control, Division of Electrical Engineering, Engineering Faculty, National Autonomous University of Mexico, 04510 Mexico City (Mexico)], E-mail: lfridman@servidor.unam.mx

    2009-12-15

    The reduced-order synchronization problem of two chaotic systems (master-slave) with different dimension and relative degree is considered. A control scheme based on a high-order sliding-mode observer-identifier and a feedback state controller is proposed, where the trajectories of slave can be synchronized with a canonical projection of the master. Thus, the reduced-order synchronization is achieved in spite of master/slave mismatches. Simulation results are provided in order to illustrate the performance of the proposed synchronization scheme.

  8. Synchronization in reduced-order of chaotic systems via control approaches based on high-order sliding-mode observer

    International Nuclear Information System (INIS)

    Rodriguez, A.; De Leon, J.; Fridman, L.

    2009-01-01

    The reduced-order synchronization problem of two chaotic systems (master-slave) with different dimension and relative degree is considered. A control scheme based on a high-order sliding-mode observer-identifier and a feedback state controller is proposed, where the trajectories of slave can be synchronized with a canonical projection of the master. Thus, the reduced-order synchronization is achieved in spite of master/slave mismatches. Simulation results are provided in order to illustrate the performance of the proposed synchronization scheme.

  9. Distributed-observer-based cooperative control for synchronization of linear discrete-time multi-agent systems.

    Science.gov (United States)

    Liang, Hongjing; Zhang, Huaguang; Wang, Zhanshan

    2015-11-01

    This paper considers output synchronization of discrete-time multi-agent systems with directed communication topologies. The directed communication graph contains a spanning tree and the exosystem as its root. Distributed observer-based consensus protocols are proposed, based on the relative outputs of neighboring agents. A multi-step algorithm is presented to construct the observer-based protocols. In light of the discrete-time algebraic Riccati equation and internal model principle, synchronization problem is completed. At last, numerical simulation is provided to verify the effectiveness of the theoretical results. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  10. The Nature of Reflective Practice and Emotional Intelligence in Tutorial Settings

    Science.gov (United States)

    Gill, Gobinder Singh

    2014-01-01

    The purpose of this paper was to assess the nature of reflective practice and emotional intelligence in tutorial settings. Following the completion of a self-report measure of emotional intelligence, practitioners incorporated a model of reflective practice into their tutorial sessions. Practitioners were instructed to utilise reflective practice…

  11. Medical imaging informatics simulators: a tutorial.

    Science.gov (United States)

    Huang, H K; Deshpande, Ruchi; Documet, Jorge; Le, Anh H; Lee, Jasper; Ma, Kevin; Liu, Brent J

    2014-05-01

    A medical imaging informatics infrastructure (MIII) platform is an organized method of selecting tools and synthesizing data from HIS/RIS/PACS/ePR systems with the aim of developing an imaging-based diagnosis or treatment system. Evaluation and analysis of these systems can be made more efficient by designing and implementing imaging informatics simulators. This tutorial introduces the MIII platform and provides the definition of treatment/diagnosis systems, while primarily focusing on the development of the related simulators. A medical imaging informatics (MII) simulator in this context is defined as a system integration of many selected imaging and data components from the MIII platform and clinical treatment protocols, which can be used to simulate patient workflow and data flow starting from diagnostic procedures to the completion of treatment. In these processes, DICOM and HL-7 standards, IHE workflow profiles, and Web-based tools are emphasized. From the information collected in the database of a specific simulator, evidence-based medicine can be hypothesized to choose and integrate optimal clinical decision support components. Other relevant, selected clinical resources in addition to data and tools from the HIS/RIS/PACS and ePRs platform may also be tailored to develop the simulator. These resources can include image content indexing, 3D rendering with visualization, data grid and cloud computing, computer-aided diagnosis (CAD) methods, specialized image-assisted surgical, and radiation therapy technologies. Five simulators will be discussed in this tutorial. The PACS-ePR simulator with image distribution is the cradle of the other simulators. It supplies the necessary PACS-based ingredients and data security for the development of four other simulators: the data grid simulator for molecular imaging, CAD-PACS, radiation therapy simulator, and image-assisted surgery simulator. The purpose and benefits of each simulator with respect to its clinical relevance

  12. Synchronous implementation of optoelectronic NOR and XNOR logic gates using parallel synchronization of three chaotic lasers

    International Nuclear Information System (INIS)

    Yan Sen-Lin

    2014-01-01

    The parallel synchronization of three chaotic lasers is used to emulate optoelectronic logic NOR and XNOR gates via modulating the light and the current. We deduce a logical computational equation that governs the chaotic synchronization, logical input, and logical output. We construct fundamental gates based on the three chaotic lasers and define the computational principle depending on the parallel synchronization. The logic gate can be implemented by appropriately synchronizing two chaotic lasers. The system shows practicability and flexibility because it can emulate synchronously an XNOR gate, two NOR gates, and so on. The synchronization can still be deteceted when mismatches exist with a certain range. (general)

  13. Local time dependences of electron flux changes during substorms derived from mulit-satellite observation at synchronous orbit

    International Nuclear Information System (INIS)

    Nagai, T.

    1982-01-01

    Energetic electron (energy higher than 2 MeV) observation by a synchronous satellite chain (which consists of GOES 2, GOES 3, and GMS covering the local time extent of approximately 10 hr) have been used to study the large-scale characteristics of the dynamic behavior in the near-earth magnetosphere for substorms, in which low-latitude positive bay aspects are clearly seen in the ground magnetic data. Simultaneous multi-satellite observations have clearly demonstrated the local time dependence of electron flux changes during substorms and the longitudinal extent of electron flux variations. Before a ground substorm onset the energetic electron flux decreases in a wide longitudinal region of the nighttime and the flux decrease is seen even on the afternoonside. For the flux behavior associated with the onset of the substorm expansion phase, there exists a demarcation line, the LT position of which can be represented as LT = 24.3-1.5 K/sub p/. The flux shows a recovery to a normal level east of the demarcation line, and it shows a decrease west of the demarcation line. The region of the flux decrease during the expansion phase is restricted, and it is observed mainly on the afternoonside. The afternoonside flux decrease has a different characteristic from the nightside flux decrease preceding the expansion phase. The nighside flux decrease-recovery sequence is observed in a wide region of more than 6 hr in the nighttime and the center of this variation exists in the premidnight region. It should be noted that the afternoonside flux decrease is not observed for every substorm and the nightside signature noted that the afternoonside flux sometimes becomes a dominent feature even on the afternoonside

  14. Modeling and Analysis of Cellular Networks using Stochastic Geometry: A Tutorial

    KAUST Repository

    Elsawy, Hesham; Salem, Ahmed Sultan; Alouini, Mohamed-Slim; Win, Moe Z.

    2016-01-01

    This paper presents a tutorial on stochastic geometry (SG) based analysis for cellular networks. This tutorial is distinguished by its depth with respect to wireless communication details and its focus on cellular networks. The paper starts by modeling and analyzing the baseband interference in a baseline single-tier downlink cellular network with single antenna base stations and universal frequency reuse. Then, it characterizes signal-to-interference-plus-noise-ratio (SINR) and its related performance metrics. In particular, a unified approach to conduct error probability, outage probability, and transmission rate analysis is presented. Although the main focus of the paper is on cellular networks, the presented unified approach applies for other types of wireless networks that impose interference protection around receivers. The paper then extends the unified approach to capture cellular network characteristics (e.g., frequency reuse, multiple antenna, power control, etc.). It also presents numerical examples associated with demonstrations and discussions. To this end, the paper highlights the state-of-the- art research and points out future research directions.

  15. Modeling and Analysis of Cellular Networks using Stochastic Geometry: A Tutorial

    KAUST Repository

    Elsawy, Hesham

    2016-11-03

    This paper presents a tutorial on stochastic geometry (SG) based analysis for cellular networks. This tutorial is distinguished by its depth with respect to wireless communication details and its focus on cellular networks. The paper starts by modeling and analyzing the baseband interference in a baseline single-tier downlink cellular network with single antenna base stations and universal frequency reuse. Then, it characterizes signal-to-interference-plus-noise-ratio (SINR) and its related performance metrics. In particular, a unified approach to conduct error probability, outage probability, and transmission rate analysis is presented. Although the main focus of the paper is on cellular networks, the presented unified approach applies for other types of wireless networks that impose interference protection around receivers. The paper then extends the unified approach to capture cellular network characteristics (e.g., frequency reuse, multiple antenna, power control, etc.). It also presents numerical examples associated with demonstrations and discussions. To this end, the paper highlights the state-of-the- art research and points out future research directions.

  16. Application of Synchronous Text-Based Dialogue Systems in Mental Health Interventions: Systematic Review.

    Science.gov (United States)

    Hoermann, Simon; McCabe, Kathryn L; Milne, David N; Calvo, Rafael A

    2017-07-21

    Synchronous written conversations (or "chats") are becoming increasingly popular as Web-based mental health interventions. Therefore, it is of utmost importance to evaluate and summarize the quality of these interventions. The aim of this study was to review the current evidence for the feasibility and effectiveness of online one-on-one mental health interventions that use text-based synchronous chat. A systematic search was conducted of the databases relevant to this area of research (Medical Literature Analysis and Retrieval System Online [MEDLINE], PsycINFO, Central, Scopus, EMBASE, Web of Science, IEEE, and ACM). There were no specific selection criteria relating to the participant group. Studies were included if they reported interventions with individual text-based synchronous conversations (ie, chat or text messaging) and a psychological outcome measure. A total of 24 articles were included in this review. Interventions included a wide range of mental health targets (eg, anxiety, distress, depression, eating disorders, and addiction) and intervention design. Overall, compared with the waitlist (WL) condition, studies showed significant and sustained improvements in mental health outcomes following synchronous text-based intervention, and post treatment improvement equivalent but not superior to treatment as usual (TAU) (eg, face-to-face and telephone counseling). Feasibility studies indicate substantial innovation in this area of mental health intervention with studies utilizing trained volunteers and chatbot technologies to deliver interventions. While studies of efficacy show positive post-intervention gains, further research is needed to determine whether time requirements for this mode of intervention are feasible in clinical practice. ©Simon Hoermann, Kathryn L McCabe, David N Milne, Rafael A Calvo. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 21.07.2017.

  17. Synchronization control of cross-strict feedback hyperchaotic system based on cross active backstepping design

    International Nuclear Information System (INIS)

    Wang Jing; Gao Jinfeng; Ma Xikui

    2007-01-01

    This Letter presents a novel cross active backstepping design method for synchronization control of cross-strict feedback hyperchaotic system, in which the ordinary backstepping design is unavailable. The proposed control method, combining backstepping design and active control approach, extends the application of backstepping technique in chaos control. Based on this method, different combinations of controllers can be designed to meet the needs of different applications. The proposed method is applied to achieve chaos synchronization of two identical cross-strict feedback hyperchaotic systems. Also it is used to implement synchronization between cross-strict feedback hyperchaotic system and Roessler hyperchaotic system. Numerical examples illustrate the validity of the control method

  18. A Memristor-Based Hyperchaotic Complex Lü System and Its Adaptive Complex Generalized Synchronization

    Directory of Open Access Journals (Sweden)

    Shibing Wang

    2016-02-01

    Full Text Available This paper introduces a new memristor-based hyperchaotic complex Lü system (MHCLS and investigates its adaptive complex generalized synchronization (ACGS. Firstly, the complex system is constructed based on a memristor-based hyperchaotic real Lü system, and its properties are analyzed theoretically. Secondly, its dynamical behaviors, including hyperchaos, chaos, transient phenomena, as well as periodic behaviors, are explored numerically by means of bifurcation diagrams, Lyapunov exponents, phase portraits, and time history diagrams. Thirdly, an adaptive controller and a parameter estimator are proposed to realize complex generalized synchronization and parameter identification of two identical MHCLSs with unknown parameters based on Lyapunov stability theory. Finally, the numerical simulation results of ACGS and its applications to secure communication are presented to verify the feasibility and effectiveness of the proposed method.

  19. Tutorial on nuclear thermal propulsion safety for Mars

    International Nuclear Information System (INIS)

    Buden, D.

    1992-01-01

    Safety is the prime design requirement for nuclear thermal propulsion (NTP). It must be built in at the initiation of the design process. An understanding of safety concerns is fundamental to the development of nuclear rockets for manned missions to Mars and many other applications that will be enabled or greatly enhanced by the use of nuclear propulsion. To provide an understanding of the basic issues, a tutorial has been prepared. This tutorial covers a range of topics including safety requirements and approaches to meet these requirements, risk and safety analysis methodology, NERVA reliability and safety approach, and life cycle risk assessments

  20. Novel Blind Recognition Algorithm of Frame Synchronization Words Based on Soft-Decision in Digital Communication Systems.

    Directory of Open Access Journals (Sweden)

    Jiangyi Qin

    Full Text Available A novel blind recognition algorithm of frame synchronization words is proposed to recognize the frame synchronization words parameters in digital communication systems. In this paper, a blind recognition method of frame synchronization words based on the hard-decision is deduced in detail. And the standards of parameter recognition are given. Comparing with the blind recognition based on the hard-decision, utilizing the soft-decision can improve the accuracy of blind recognition. Therefore, combining with the characteristics of Quadrature Phase Shift Keying (QPSK signal, an improved blind recognition algorithm based on the soft-decision is proposed. Meanwhile, the improved algorithm can be extended to other signal modulation forms. Then, the complete blind recognition steps of the hard-decision algorithm and the soft-decision algorithm are given in detail. Finally, the simulation results show that both the hard-decision algorithm and the soft-decision algorithm can recognize the parameters of frame synchronization words blindly. What's more, the improved algorithm can enhance the accuracy of blind recognition obviously.

  1. Linear Extended State Observer-Based Motion Synchronization Control for Hybrid Actuation System of More Electric Aircraft

    Directory of Open Access Journals (Sweden)

    Xingjian Wang

    2017-10-01

    Full Text Available Moving towards the more electric aircraft (MEA, a hybrid actuator configuration provides an opportunity to introduce electromechanical actuator (EMA into primary flight control. In the hybrid actuation system (HAS, an electro-hydraulic servo actuator (EHSA and an EMA operate on the same control surface. In order to solve force fighting problem in HAS, this paper proposes a novel linear extended state observer (LESO-based motion synchronization control method. To cope with the problem of unavailability of the state signals required by the motion synchronization controller, LESO is designed for EHSA and EMA to observe the state variables. Based on the observed states of LESO, motion synchronization controllers could enable EHSA and EMA to simultaneously track the desired motion trajectories. Additionally, nonlinearities, uncertainties and unknown disturbances as well as the coupling term between EHSA and EMA can be estimated and compensated by using the extended state of the proposed LESO. Finally, comparative simulation results indicate that the proposed LESO-based motion synchronization controller could reduce significant force fighting between EHSA and EMA.

  2. Linear Extended State Observer-Based Motion Synchronization Control for Hybrid Actuation System of More Electric Aircraft

    Science.gov (United States)

    Liao, Rui; Shi, Cun; Wang, Shaoping

    2017-01-01

    Moving towards the more electric aircraft (MEA), a hybrid actuator configuration provides an opportunity to introduce electromechanical actuator (EMA) into primary flight control. In the hybrid actuation system (HAS), an electro-hydraulic servo actuator (EHSA) and an EMA operate on the same control surface. In order to solve force fighting problem in HAS, this paper proposes a novel linear extended state observer (LESO)-based motion synchronization control method. To cope with the problem of unavailability of the state signals required by the motion synchronization controller, LESO is designed for EHSA and EMA to observe the state variables. Based on the observed states of LESO, motion synchronization controllers could enable EHSA and EMA to simultaneously track the desired motion trajectories. Additionally, nonlinearities, uncertainties and unknown disturbances as well as the coupling term between EHSA and EMA can be estimated and compensated by using the extended state of the proposed LESO. Finally, comparative simulation results indicate that the proposed LESO-based motion synchronization controller could reduce significant force fighting between EHSA and EMA. PMID:29068392

  3. Programming a real-time operating system for satellite control applications Satellite Control Applications

    International Nuclear Information System (INIS)

    Omer, M.; Anjum, O.; Suddle, M.R.

    2004-01-01

    With the realization of ideas like formation flights and multi-body space vehicles the demands on an attitude control system have become increasingly complex. Even in its most simplified form, the control system for a typical geostationary satellite has to run various supervisory functions along with determination and control algorithms side by side. Within each algorithm it has to employ multiple actuation and sensing mechanisms and service real time interrupts, for example, in the case of actuator saturation and sensor data fusion. This entails the idea of thread scheduling and program synchronization, tasks specifically meant for a real time OS. This paper explores the embedding of attitude determination and control loop within the framework of a real time operating system provided for TI's DSP C6xxx series. The paper details out the much functionality provided within the scaleable real time kernel and the analysis and configuration tools available, It goes on to describe a layered implementation stack associated with a typical control for Geo Stationary satellites. An application for control is then presented in which state of the art analysis tools are employed to view program threads, synchronization semaphores, hardware interrupts and data exchange pipes operating in real time. (author)

  4. An example of using CASPER tutorials for teaching knowledge of firmware development for FPGAs

    International Nuclear Information System (INIS)

    Pollak, A.W.

    2015-01-01

    We present an example of using CASPER tutorials for teaching purposes in Summer Schools and Workshops with participants from a variety of different academic backgrounds. Using the tutorials for laboratory exercises at the INFIERI Summer School 2014, we showed that the flexible nature provided by these tutorials has the advantage of providing high quality laboratory exercises for participants independent of their prior knowledge

  5. Multiple access chaotic digital communication based on generalized synchronization

    International Nuclear Information System (INIS)

    Lu Junguo

    2005-01-01

    A novel method for multiple access chaotic digital communication based on the concept of chaos generalized synchronization and the on-line least square method is proposed. This method can be used for transmitting multiple digital information signals concurrently. We illustrate the method using a Lorenz system driving a Chua's circuit and then examine the robustness of the proposed method with respect to noise in communication channel

  6. Characterizing representational learning: A combined simulation and tutorial on perturbation theory

    Directory of Open Access Journals (Sweden)

    Antje Kohnle

    2017-11-01

    Full Text Available Analyzing, constructing, and translating between graphical, pictorial, and mathematical representations of physics ideas and reasoning flexibly through them (“representational competence” is a key characteristic of expertise in physics but is a challenge for learners to develop. Interactive computer simulations and University of Washington style tutorials both have affordances to support representational learning. This article describes work to characterize students’ spontaneous use of representations before and after working with a combined simulation and tutorial on first-order energy corrections in the context of quantum-mechanical time-independent perturbation theory. Data were collected from two institutions using pre-, mid-, and post-tests to assess short- and long-term gains. A representational competence level framework was adapted to devise level descriptors for the assessment items. The results indicate an increase in the number of representations used by students and the consistency between them following the combined simulation tutorial. The distributions of representational competence levels suggest a shift from perceptual to semantic use of representations based on their underlying meaning. In terms of activity design, this study illustrates the need to support students in making sense of the representations shown in a simulation and in learning to choose the most appropriate representation for a given task. In terms of characterizing representational abilities, this study illustrates the usefulness of a framework focusing on perceptual, syntactic, and semantic use of representations.

  7. Characterizing representational learning: A combined simulation and tutorial on perturbation theory

    Science.gov (United States)

    Kohnle, Antje; Passante, Gina

    2017-12-01

    Analyzing, constructing, and translating between graphical, pictorial, and mathematical representations of physics ideas and reasoning flexibly through them ("representational competence") is a key characteristic of expertise in physics but is a challenge for learners to develop. Interactive computer simulations and University of Washington style tutorials both have affordances to support representational learning. This article describes work to characterize students' spontaneous use of representations before and after working with a combined simulation and tutorial on first-order energy corrections in the context of quantum-mechanical time-independent perturbation theory. Data were collected from two institutions using pre-, mid-, and post-tests to assess short- and long-term gains. A representational competence level framework was adapted to devise level descriptors for the assessment items. The results indicate an increase in the number of representations used by students and the consistency between them following the combined simulation tutorial. The distributions of representational competence levels suggest a shift from perceptual to semantic use of representations based on their underlying meaning. In terms of activity design, this study illustrates the need to support students in making sense of the representations shown in a simulation and in learning to choose the most appropriate representation for a given task. In terms of characterizing representational abilities, this study illustrates the usefulness of a framework focusing on perceptual, syntactic, and semantic use of representations.

  8. Action perception and imitation : a tutorial

    NARCIS (Netherlands)

    Bekkering, H; Wohlschlager, A; Prinz, W; Hommel, B

    2002-01-01

    Currently, imitation, or performing an act after perceiving it, is in the focus of attention of researchers from many different disciplines. Although this tutorial attempts to provide some interdisciplinary background, it will concentrate on possible cognitive mechanisms that underlie imitation

  9. Integrating Satellite, Radar and Surface Observation with Time and Space Matching

    Science.gov (United States)

    Ho, Y.; Weber, J.

    2015-12-01

    The Integrated Data Viewer (IDV) from Unidata is a Java™-based software framework for analyzing and visualizing geoscience data. It brings together the ability to display and work with satellite imagery, gridded data, surface observations, balloon soundings, NWS WSR-88D Level II and Level III RADAR data, and NOAA National Profiler Network data, all within a unified interface. Applying time and space matching on the satellite, radar and surface observation datasets will automatically synchronize the display from different data sources and spatially subset to match the display area in the view window. These features allow the IDV users to effectively integrate these observations and provide 3 dimensional views of the weather system to better understand the underlying dynamics and physics of weather phenomena.

  10. RBF neural network based H∞ synchronization for unknown chaotic ...

    Indian Academy of Sciences (India)

    , 172 ... the effect of disturbance to an H∞ norm constraint. It is shown that ... unknown chaotic systems; linear matrix inequality (LMI); learning law. 1. Introduction .... (9) is RBFNN H∞ synchronized if the synchronization error e(t) satisfies. ∫ ∞.

  11. Biologically Inspired Intercellular Slot Synchronization

    Directory of Open Access Journals (Sweden)

    Alexander Tyrrell

    2009-01-01

    Full Text Available The present article develops a decentralized interbase station slot synchronization algorithm suitable for cellular mobile communication systems. The proposed cellular firefly synchronization (CelFSync algorithm is derived from the theory of pulse-coupled oscillators, common to describe synchronization phenomena in biological systems, such as the spontaneous synchronization of fireflies. In order to maintain synchronization among base stations (BSs, even when there is no direct link between adjacent BSs, some selected user terminals (UTs participate in the network synchronization process. Synchronization emerges by exchanging two distinct synchronization words, one transmitted by BSs and the other by active UTs, without any a priori assumption on the initial timing misalignments of BSs and UTs. In large-scale networks with inter-BS site distances up to a few kilometers, propagation delays severely affect the attainable timing accuracy of CelFSync. We show that by an appropriate combination of CelFSync with the timing advance procedure, which aligns uplink transmission of UTs to arrive simultaneously at the BS, a timing accuracy within a fraction of the inter-BS propagation delay is retained.

  12. Linear-control-based synchronization of coexisting attractor networks with time delays

    International Nuclear Information System (INIS)

    Yun-Zhong, Song

    2010-01-01

    This paper introduces the concept of linear-control-based synchronization of coexisting attractor networks with time delays. Within the new framework, closed loop control for each dynamic node is realized through linear state feedback around its own arena in a decentralized way, where the feedback matrix is determined through consideration of the coordination of the node dynamics, the inner connected matrix and the outer connected matrix. Unlike previously existing results, the feedback gain matrix here is decoupled from the inner matrix; this not only guarantees the flexible choice of the gain matrix, but also leaves much space for inner matrix configuration. Synchronization of coexisting attractor networks with time delays is made possible in virtue of local interaction, which works in a distributed way between individual neighbours, and the linear feedback control for each node. Provided that the network is connected and balanced, synchronization will come true naturally, where theoretical proof is given via a Lyapunov function. For completeness, several illustrative examples are presented to further elucidate the novelty and efficacy of the proposed scheme. (general)

  13. Analysis of Synchronization Impairments for Cooperative Base Stations Using OFDM

    Directory of Open Access Journals (Sweden)

    Konstantinos Manolakis

    2015-01-01

    Full Text Available Base station cooperation is envisioned as a key technology for future cellular networks, as it has the potential to eliminate intercell interference and to enhance spectral efficiency. To date, there is still lack of understanding of how imperfect carrier and sampling frequency synchronization between transmitters and receivers limit the potential gains and what the actual system requirements are. In this paper, OFDM signal model is established for multiuser multicellular networks, describing the joint effect of multiple carrier and sampling frequency offsets. It is shown that the impact of sampling offsets is much smaller than the impact of carrier frequency offsets. The model is extended to the downlink of base-coordinated networks and closed-form expressions are derived for the mean power of users’ self-signal, interuser, and intercarrier interference, whereas it is shown that interuser interference is the main source of degradation. The SIR is inverse to the base stations’ carrier frequency variance and to the square of time since the last precoder update, whereas it grows with the number of base stations and drops with the number of users. Through user selection, the derived SIR upper bound can be approached. Finally, system design recommendations for meeting synchronization requirements are provided.

  14. Synchronization of random bit generators based on coupled chaotic lasers and application to cryptography.

    Science.gov (United States)

    Kanter, Ido; Butkovski, Maria; Peleg, Yitzhak; Zigzag, Meital; Aviad, Yaara; Reidler, Igor; Rosenbluh, Michael; Kinzel, Wolfgang

    2010-08-16

    Random bit generators (RBGs) constitute an important tool in cryptography, stochastic simulations and secure communications. The later in particular has some difficult requirements: high generation rate of unpredictable bit strings and secure key-exchange protocols over public channels. Deterministic algorithms generate pseudo-random number sequences at high rates, however, their unpredictability is limited by the very nature of their deterministic origin. Recently, physical RBGs based on chaotic semiconductor lasers were shown to exceed Gbit/s rates. Whether secure synchronization of two high rate physical RBGs is possible remains an open question. Here we propose a method, whereby two fast RBGs based on mutually coupled chaotic lasers, are synchronized. Using information theoretic analysis we demonstrate security against a powerful computational eavesdropper, capable of noiseless amplification, where all parameters are publicly known. The method is also extended to secure synchronization of a small network of three RBGs.

  15. Chaos synchronization of coupled hyperchaotic system

    International Nuclear Information System (INIS)

    Yang Lixin; Chu Yandong; Zhang Jiangang; Li Xianfeng

    2009-01-01

    Chaos synchronization, as an important topic, has become an active research subject in nonlinear science. Over the past two decades, chaos synchronization between nonlinear systems has been extensively studied, and many types of synchronization have been announced. This paper introduces synchronization of coupled hyperchaotic system, based on the Lapunov stability theory, asymptotic stability of the system is guaranteed by means of Lapunov function. The numerical simulation was provided in order to show the effectiveness of this method for the synchronization of the chaotic hyperchaotic Chen system and Rossler system.

  16. CERN Technical Training 2007: IT3T - IT Technical Training Tutorials (Autumn 2007)

    CERN Multimedia

    2007-01-01

    CERN Technical Training and the Internet Services group of the IT department (IT/IS) are jointly organizing a series of free tutorials, addressing some topics of common interest: the IT Technical Training Tutorials (IT3T). The first IT3T series will be offered in October 2007, in French, with the following schedule: IT3T/2007/1 "Introduction to Collaboration Workspaces using SharePoint", October 23rd , 14:30-16:00, Alexandre Lossent IT3T/2007/2 "What is new in Office 2007", October 25th, 14:30-15:30, Emmanuel Ormancey IT3T/2007/3 "Working with Windows Vista at CERN", October 30th, 14:30-15:30, Michal Kwiatek IT3T/2007/4 "Read your mail and more with Outlook 2007", November 1st, 14:30-15:30, Sebastien Dellabella All IT Technical Training Tutorials will take place in the Training Centre Auditorium (building 593, room 11), at 14h30. The tutorials are free of charge, but separate registration to each is required. Participation to any of the tutorials is open: attendance to any ...

  17. Optical burst switching based satellite backbone network

    Science.gov (United States)

    Li, Tingting; Guo, Hongxiang; Wang, Cen; Wu, Jian

    2018-02-01

    We propose a novel time slot based optical burst switching (OBS) architecture for GEO/LEO based satellite backbone network. This architecture can provide high speed data transmission rate and high switching capacity . Furthermore, we design the control plane of this optical satellite backbone network. The software defined network (SDN) and network slice (NS) technologies are introduced. Under the properly designed control mechanism, this backbone network is flexible to support various services with diverse transmission requirements. Additionally, the LEO access and handoff management in this network is also discussed.

  18. Hyperspectral image analysis. A tutorial

    International Nuclear Information System (INIS)

    Amigo, José Manuel; Babamoradi, Hamid; Elcoroaristizabal, Saioa

    2015-01-01

    This tutorial aims at providing guidelines and practical tools to assist with the analysis of hyperspectral images. Topics like hyperspectral image acquisition, image pre-processing, multivariate exploratory analysis, hyperspectral image resolution, classification and final digital image processing will be exposed, and some guidelines given and discussed. Due to the broad character of current applications and the vast number of multivariate methods available, this paper has focused on an industrial chemical framework to explain, in a step-wise manner, how to develop a classification methodology to differentiate between several types of plastics by using Near infrared hyperspectral imaging and Partial Least Squares – Discriminant Analysis. Thus, the reader is guided through every single step and oriented in order to adapt those strategies to the user's case. - Highlights: • Comprehensive tutorial of Hyperspectral Image analysis. • Hierarchical discrimination of six classes of plastics containing flame retardant. • Step by step guidelines to perform class-modeling on hyperspectral images. • Fusion of multivariate data analysis and digital image processing methods. • Promising methodology for real-time detection of plastics containing flame retardant.

  19. Chaos Synchronization Based on Unknown Input Proportional Multiple-Integral Fuzzy Observer

    Directory of Open Access Journals (Sweden)

    T. Youssef

    2013-01-01

    Full Text Available This paper presents an unknown input Proportional Multiple-Integral Observer (PIO for synchronization of chaotic systems based on Takagi-Sugeno (TS fuzzy chaotic models subject to unmeasurable decision variables and unknown input. In a secure communication configuration, this unknown input is regarded as a message encoded in the chaotic system and recovered by the proposed PIO. Both states and outputs of the fuzzy chaotic models are subject to polynomial unknown input with kth derivative zero. Using Lyapunov stability theory, sufficient design conditions for synchronization are proposed. The PIO gains matrices are obtained by resolving linear matrix inequalities (LMIs constraints. Simulation results show through two TS fuzzy chaotic models the validity of the proposed method.

  20. Security analysis of communication system based on the synchronization of different order chaotic systems

    International Nuclear Information System (INIS)

    Alvarez, Gonzalo; Hernandez, Luis; Munoz, Jaime; Montoya, Fausto; Li Shujun

    2005-01-01

    This Letter analyzes the security weakness of a recently proposed communication method based on chaotic modulation and masking using synchronization of two chaotic systems with different orders. It is shown that its application to secure communication is unsafe, because it can be broken in two different ways, by high-pass filtering and by reduced order system synchronization, without knowing neither the system parameter values nor the system key

  1. TUTORIAL: Focused-ion-beam-based rapid prototyping of nanoscale magnetic devices

    Science.gov (United States)

    Khizroev, S.; Litvinov, D.

    2004-03-01

    In this tutorial, focused-ion-beam (FIB)-based fabrication is considered from a very unconventional angle. FIB is considered not as a fabrication tool that can be used for mass production of electronic devices, similar to optical and E-beam—based lithography, but rather as a powerful tool to rapidly fabricate individual nanoscale magnetic devices for prototyping future electronic applications. Among the effects of FIB-based fabrication of magnetic devices, the influence of Ga+-ion implantation on magnetic properties is presented. With help of magnetic force microscopy (MFM), it is shown that there is a critical doze of ions that a magnetic material can be exposed to without experiencing a change in the magnetic properties. Exploiting FIB from such an unconventional perspective is especially favourable today when the future of so many novel technologies depends on the ability to rapidly fabricate prototype nanoscale magnetic devices. As one of the most illustrative examples, the multi-billion-dollar data storage industry is analysed as the technology field that strongly benefited from implementing FIB in the above-described role. The essential role of FIB in the most recent trend of the industry towards perpendicular magnetic recording is presented. Moreover, other emerging and fast-growing technologies are considered as examples of nanoscale technologies whose future could strongly depend on the implementation of FIB in the role of a nanoscale fabrication tool for rapid prototyping. Among the other described technologies are 'ballistic' magnetoresistance, patterned magnetic media, magnetoresistive RAM (MRAM), and magnetic force microscopy.

  2. Tutorial on X-ray photon counting detector characterization.

    Science.gov (United States)

    Ren, Liqiang; Zheng, Bin; Liu, Hong

    2018-01-01

    Recent advances in photon counting detection technology have led to significant research interest in X-ray imaging. As a tutorial level review, this paper covers a wide range of aspects related to X-ray photon counting detector characterization. The tutorial begins with a detailed description of the working principle and operating modes of a pixelated X-ray photon counting detector with basic architecture and detection mechanism. Currently available methods and techniques for charactering major aspects including energy response, noise floor, energy resolution, count rate performance (detector efficiency), and charge sharing effect of photon counting detectors are comprehensively reviewed. Other characterization aspects such as point spread function (PSF), line spread function (LSF), contrast transfer function (CTF), modulation transfer function (MTF), noise power spectrum (NPS), detective quantum efficiency (DQE), bias voltage, radiation damage, and polarization effect are also remarked. A cadmium telluride (CdTe) pixelated photon counting detector is employed for part of the characterization demonstration and the results are presented. This review can serve as a tutorial for X-ray imaging researchers and investigators to understand, operate, characterize, and optimize photon counting detectors for a variety of applications.

  3. Symbol synchronization and sampling frequency synchronization techniques in real-time DDO-OFDM systems

    Science.gov (United States)

    Chen, Ming; He, Jing; Cao, Zizheng; Tang, Jin; Chen, Lin; Wu, Xian

    2014-09-01

    In this paper, we propose and experimentally demonstrate a symbol synchronization and sampling frequency synchronization techniques in real-time direct-detection optical orthogonal frequency division multiplexing (DDO-OFDM) system, over 100-km standard single mode fiber (SSMF) using a cost-effective directly modulated distributed feedback (DFB) laser. The experiment results show that the proposed symbol synchronization based on training sequence (TS) has a low complexity and high accuracy even at a sampling frequency offset (SFO) of 5000-ppm. Meanwhile, the proposed pilot-assisted sampling frequency synchronization between digital-to-analog converter (DAC) and analog-to-digital converter (ADC) is capable of estimating SFOs with an accuracy of technique can also compensate SFO effects within a small residual SFO caused by deviation of SFO estimation and low-precision or unstable clock source. The two synchronization techniques are suitable for high-speed DDO-OFDM transmission systems.

  4. High-Order Sliding Mode-Based Synchronous Control of a Novel Stair-Climbing Wheelchair Robot

    Directory of Open Access Journals (Sweden)

    Juanxiu Liu

    2015-01-01

    Full Text Available For the attitude control of a novel stair-climbing wheelchair with inertial uncertainties and external disturbance torques, a new synchronous control method is proposed via combing high-order sliding mode control techniques with cross-coupling techniques. For this purpose, a proper controller is designed, which can improve the performance of the system under conditions of uncertainties and torque perturbations and also can guarantee the synchronization of the system. Firstly, a robust high-order sliding mode control law is designed to track the desired position trajectories effectively. Secondly, considering the coordination of the multiple joints, a high-order sliding mode synchronization controller is designed to reduce the synchronization errors and tracking errors based on the controller designed previously. Stability of the closed-loop system is proved by Lyapunov theory. The simulation is performed by MATLAB to verify the effectiveness of the proposed controller. By comparing the simulation results of two controllers, it is obvious that the proposed scheme has better performance and stronger robustness.

  5. Fast Self-Synchronization between LowVoltage Microgrid and Inverter using Virtual Synchronous Converter

    Directory of Open Access Journals (Sweden)

    Md Ruhul Amin

    2017-12-01

    Full Text Available In this paper, a fast self-synchronization known as virtual synchronous converter (VSCon between single-phase microgrid and inverter in low-voltage microgrid, has been developed in Matlab/Simulink. The idea is to any phase locked loop (PLL circuit for inverter-microgrid synchronization in order to improve the synchronization time. As known, it is difficult and lengthy process to tune the PLL gain parameters to reach suitable performance for synchronizing among the voltage, phase-angle and frequency between them. Due to this problem, a fast self synchronization technique is needed in order to minimize the time losses at the microgrid connection. Therefore, the VSCon has been developed which is based on the synchronous generator mathematical model but in virtual environment representation. It has been applied in the inverter control for generating switching pattern to the inverter switches in order to respond to the grid voltage for improve the synchronization. For a prove of concept, several simulation tests in MATLAB models have been conducted, in order to see the effectiveness of this VSCon. First test has been conducted, when a 240V, 50Hz frequency grid source is used for observing the self-synchronization the system with the power flows output. Furthermore, the next test is conducted when the grid frequency is changed from the rated frequency at 50Hz to 51Hz and the result shows the VSCon in inverter control takes nearly 40ms to synchronize to this new frequency value. The test on grid phase-angle delay also been tested when ac grid voltage has 150 phase delay. As from all the results, the improved inverter control with VSCon structure is able to have fast and self-synchronized between the invertergrid connection before the power from the inverter can be transferred.

  6. Global Warming: Evidence from Satellite Observations

    Science.gov (United States)

    Prabhakara, C.; Iacovazzi, R., Jr.; Yoo, J.-M.

    2001-01-01

    Observations made in Channel 2 (53.74 GHz) of the Microwave Sounding Unit (MSU) radiometer, flown on-board sequential, sun-synchronous, polar orbiting NOAA operational satellites, indicate that the mean temperature of the atmosphere over the globe increased during the period 1980 to 1999. In this study we have minimized systematic errors in the time series introduced by the satellite orbital drift in an objective manner. This is done with the help the onboard warm black body temperature, which is used in the calibration of the MSU radiometer. The corrected MSU Channel 2 observations of the NOAA satellite series reveal that the vertically weighted global mean temperature of the atmosphere, with a peak weight near the mid-troposphere, warmed at the rate of 0.13 K per decade (with an uncertainty of 0.05 K per decade) during 1980 to 1999. The global warming deduced from conventional meteorological data that have been corrected for urbanization effects agrees reasonably with this satellite deuced result.

  7. Methodology for GPS Synchronization Evaluation with High Accuracy

    OpenAIRE

    Li Zan; Braun Torsten; Dimitrova Desislava

    2015-01-01

    Clock synchronization in the order of nanoseconds is one of the critical factors for time based localization. Currently used time synchronization methods are developed for the more relaxed needs of network operation. Their usability for positioning should be carefully evaluated. In this paper we are particularly interested in GPS based time synchronization. To judge its usability for localization we need a method that can evaluate the achieved time synchronization with nanosecond accuracy. Ou...

  8. Methodology for GPS Synchronization Evaluation with High Accuracy

    OpenAIRE

    Li, Zan; Braun, Torsten; Dimitrova, Desislava Cvetanova

    2015-01-01

    Clock synchronization in the order of nanoseconds is one of the critical factors for time-based localization. Currently used time synchronization methods are developed for the more relaxed needs of network operation. Their usability for positioning should be carefully evaluated. In this paper, we are particularly interested in GPS-based time synchronization. To judge its usability for localization we need a method that can evaluate the achieved time synchronization with nanosecond accuracy. O...

  9. An Online Tutorial vs. Pre-Recorded Lecture for Reducing Incidents of Plagiarism

    Science.gov (United States)

    Henslee, Amber M.; Goldsmith, Jacob; Stone, Nancy J.; Krueger, Merilee

    2015-01-01

    The current study compared an online academic integrity tutorial modified from Belter & du Pre (2009) to a pre-recorded online academic integrity lecture in reducing incidents of plagiarism among undergraduate students at a science and technology university. Participants were randomized to complete either the tutorial or the pre-recorded…

  10. Psychosemiotics and Libraries: Identifying Signways in Library Informational Guides, Games, and Tutorials

    Science.gov (United States)

    Laster, Barbara; Blummer, Barbara; Kenton, Jeffrey M.

    2010-01-01

    Tutorials and digital learning objects provide librarians a quick, concise mechanism for delivering information and training on a wide range of library topics. The semiotic theory promoted by Charles Sanders Peirce (Wiener, 1958) and Howard Smith (2005) contains implications for enhancing the effectiveness of library tutorials through the…

  11. Network design consideration of a satellite-based mobile communications system

    Science.gov (United States)

    Yan, T.-Y.

    1986-01-01

    Technical considerations for the Mobile Satellite Experiment (MSAT-X), the ground segment testbed for the low-cost spectral efficient satellite-based mobile communications technologies being developed for the 1990's, are discussed. The Network Management Center contains a flexible resource sharing algorithm, the Demand Assigned Multiple Access scheme, which partitions the satellite transponder bandwidth among voice, data, and request channels. Satellite use of multiple UHF beams permits frequency reuse. The backhaul communications and the Telemetry, Tracking and Control traffic are provided through a single full-coverage SHF beam. Mobile Terminals communicate with the satellite using UHF. All communications including SHF-SHF between Base Stations and/or Gateways, are routed through the satellite. Because MSAT-X is an experimental network, higher level network protocols (which are service-specific) will be developed only to test the operation of the lowest three levels, the physical, data link, and network layers.

  12. Error function attack of chaos synchronization based encryption schemes.

    Science.gov (United States)

    Wang, Xingang; Zhan, Meng; Lai, C-H; Gang, Hu

    2004-03-01

    Different chaos synchronization based encryption schemes are reviewed and compared from the practical point of view. As an efficient cryptanalysis tool for chaos encryption, a proposal based on the error function attack is presented systematically and used to evaluate system security. We define a quantitative measure (quality factor) of the effective applicability of a chaos encryption scheme, which takes into account the security, the encryption speed, and the robustness against channel noise. A comparison is made of several encryption schemes and it is found that a scheme based on one-way coupled chaotic map lattices performs outstandingly well, as judged from quality factor. Copyright 2004 American Institute of Physics.

  13. Application of static var compensator on large synchronous motors based on linear optimization control design

    International Nuclear Information System (INIS)

    Soltani, J.; Fath Abadi, A.M.

    2003-01-01

    This paper describes the application of static var compensators, on an electrical distribution network containing two large synchronous motors, one of which is excited via a three-phase thyristor bridge rectifier. The second machine is excited via a diode bridge rectifier. Based on linear optimization control, the measurable feedback signals are applied to the control system loops of static var compensators and the excitation control loop of the first synchronous motor. The phase equations method was used to develop a computer program to model the distribution network. Computer results were obtained to demonstrate the system performance for some abnormal modes of operation. These results show that employing static var compensators based on the linear optimization control design for electrical distribution networks containing large synchronous motors is beneficial and may be considered a first stage of the system design

  14. Transcript for Understanding Medical Words: A Tutorial

    Science.gov (United States)

    ... medlineplus.gov/medicalwordstranscript.html Transcript for Understanding Medical Words: A Tutorial To use the sharing features on ... get to what those mean in a minute. Word Roots Word Roots. Let's begin with body parts. ...

  15. Planning for a data base system to support satellite conceptual design

    Science.gov (United States)

    Claydon, C. R.

    1976-01-01

    The conceptual design of an automated satellite design data base system is presented. The satellite catalog in the system includes data for all earth orbital satellites funded to the hardware stage for launch between 1970 and 1980, and provides a concise compilation of satellite capabilities and design parameters. The cost of satellite subsystems and components will be added to the base. Data elements are listed and discussed. Sensor and science and applications opportunities catalogs will be included in the data system. Capabilities of the BASIS storage, retrieval, and analysis system are used in the system design.

  16. First satellite mobile communication trials using BLQS-CDMA

    Science.gov (United States)

    Luzdemateo, Maria; Johns, Simon; Dothey, Michel; Vanhimbeeck, Carl; Deman, Ivan; Wery, Bruno

    1993-01-01

    In this paper, technical results obtained in the first MSBN Land mobile technical trial are reported. MSBN (Mobile Satellite Business Network) is a new program undertaken by the European Space Agency (ESA) to promote mobile satellite communication in Europe, in particular voice capability. The first phase of the MSBN system implementation plan is an experimental phase. Its purpose is to evaluate through field experiments the performance of the MSBN system prior to finalization of its specifications. Particularly, the objective is to verify in the field and possibly improve the performance of the novel satellite access technique BLQS-CDMA (Band Limited Quasi-Synchronous-Code Division Multiple Access), which is proposed as baseline for the MSBN.

  17. Synchronization of Hierarchical Time-Varying Neural Networks Based on Asynchronous and Intermittent Sampled-Data Control.

    Science.gov (United States)

    Xiong, Wenjun; Patel, Ragini; Cao, Jinde; Zheng, Wei Xing

    In this brief, our purpose is to apply asynchronous and intermittent sampled-data control methods to achieve the synchronization of hierarchical time-varying neural networks. The asynchronous and intermittent sampled-data controllers are proposed for two reasons: 1) the controllers may not transmit the control information simultaneously and 2) the controllers cannot always exist at any time . The synchronization is then discussed for a kind of hierarchical time-varying neural networks based on the asynchronous and intermittent sampled-data controllers. Finally, the simulation results are given to illustrate the usefulness of the developed criteria.In this brief, our purpose is to apply asynchronous and intermittent sampled-data control methods to achieve the synchronization of hierarchical time-varying neural networks. The asynchronous and intermittent sampled-data controllers are proposed for two reasons: 1) the controllers may not transmit the control information simultaneously and 2) the controllers cannot always exist at any time . The synchronization is then discussed for a kind of hierarchical time-varying neural networks based on the asynchronous and intermittent sampled-data controllers. Finally, the simulation results are given to illustrate the usefulness of the developed criteria.

  18. System and method for time synchronization in a wireless network

    Science.gov (United States)

    Gonia, Patrick S.; Kolavennu, Soumitri N.; Mahasenan, Arun V.; Budampati, Ramakrishna S.

    2010-03-30

    A system includes multiple wireless nodes forming a cluster in a wireless network, where each wireless node is configured to communicate and exchange data wirelessly based on a clock. One of the wireless nodes is configured to operate as a cluster master. Each of the other wireless nodes is configured to (i) receive time synchronization information from a parent node, (ii) adjust its clock based on the received time synchronization information, and (iii) broadcast time synchronization information based on the time synchronization information received by that wireless node. The time synchronization information received by each of the other wireless nodes is based on time synchronization information provided by the cluster master so that the other wireless nodes substantially synchronize their clocks with the clock of the cluster master.

  19. Indico CONFERENCE tutorial

    CERN Multimedia

    CERN. Geneva; Manzoni, Alex Marc

    2017-01-01

    This short tutorial explains how to create a CONFERENCE in indico and how to handle abstracts and registration forms, in detail: Timestamps: 1:01 - Programme  2:28 - Call for abstracts  11:50 - Abstract submission  13:41 - Abstract Review 15:41 - The Judge's Role 17:23 - Registration forms' creation 23:34 - Candidate participant's registration/application 25:54 - Customisation of Indico pages - Layout 28:08 - Customisation of Indico pages - Menus 29:47 - Configuring Event reminders and import into calendaring tools   See HERE a recent presentation by Pedro about the above steps in the life of an indico CONFERENCE event.

  20. Design and implementation of EP-based PID controller for chaos synchronization of Rikitake circuit systems.

    Science.gov (United States)

    Hou, Yi-You

    2017-09-01

    This article addresses an evolutionary programming (EP) algorithm technique-based and proportional-integral-derivative (PID) control methods are established to guarantee synchronization of the master and slave Rikitake chaotic systems. For PID synchronous control, the evolutionary programming (EP) algorithm is used to find the optimal PID controller parameters k p , k i , k d by integrated absolute error (IAE) method for the convergence conditions. In order to verify the system performance, the basic electronic components containing operational amplifiers (OPAs), resistors, and capacitors are used to implement the proposed chaotic Rikitake systems. Finally, the experimental results validate the proposed Rikitake chaotic synchronization approach. Copyright © 2017. Published by Elsevier Ltd.

  1. An approach of parameter estimation for non-synchronous systems

    International Nuclear Information System (INIS)

    Xu Daolin; Lu Fangfang

    2005-01-01

    Synchronization-based parameter estimation is simple and effective but only available to synchronous systems. To come over this limitation, we propose a technique that the parameters of an unknown physical process (possibly a non-synchronous system) can be identified from a time series via a minimization procedure based on a synchronization control. The feasibility of this approach is illustrated in several chaotic systems

  2. Synchronization of map-based neurons with memory and synaptic delay

    Energy Technology Data Exchange (ETDEWEB)

    Sausedo-Solorio, J.M. [Universidad Autónoma del Estado de Hidalgo, Carretera Pachuca-Tulancingo Km. 4.5, 42074 Pachuca, Hidalgo (Mexico); Pisarchik, A.N., E-mail: apisarch@cio.mx [Centro de Investigaciones en Optica, Loma del Bosque 115, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Centre for Biomedical Technology, Technical University of Madrid, Campus Montegancedo, 28223 Pozuelo de Alarcon, Madrid (Spain)

    2014-06-13

    Synchronization of two synaptically coupled neurons with memory and synaptic delay is studied using the Rulkov map, one of the simplest neuron models which displays specific features inherent to bursting dynamics. We demonstrate a transition from lag to anticipated synchronization as the relationship between the memory duration and the synaptic delay time changes. The neuron maps synchronize either with anticipation, if the memory is longer than the synaptic delay time, or with lag otherwise. The mean anticipation time is equal to the difference between the memory and synaptic delay independently of the coupling strength. Frequency entrainment and phase-locking phenomena as well as a transition from regular spikes to chaos are demonstrated with respect to the coupling strength. - Highlights: • We study synchronization of neurons with memory and synaptic delay in the map model. • Neurons synchronize either with anticipation or with lag depending on delay time. • Mean anticipation time is equal to the difference between memory and synaptic delay. • Frequency entrainment and phase locking are studied with respect to the coupling.

  3. Community structure in real-world networks from a non-parametrical synchronization-based dynamical approach

    International Nuclear Information System (INIS)

    Moujahid, Abdelmalik; D’Anjou, Alicia; Cases, Blanca

    2012-01-01

    Highlights: ► A synchronization-based algorithm for community structure detection is proposed. ► We model a complex network based on coupled nonidentical chaotic Rössler oscillators. ► The interaction scheme contemplates an uniformly increasing coupling force. ► The frequencies of oscillators are adapted according to a parameterless mechanism. ► The adaptation mechanism reveals the community structure present in the network. - Abstract: This work analyzes the problem of community structure in real-world networks based on the synchronization of nonidentical coupled chaotic Rössler oscillators each one characterized by a defined natural frequency, and coupled according to a predefined network topology. The interaction scheme contemplates an uniformly increasing coupling force to simulate a society in which the association between the agents grows in time. To enhance the stability of the correlated states that could emerge from the synchronization process, we propose a parameterless mechanism that adapts the characteristic frequencies of coupled oscillators according to a dynamic connectivity matrix deduced from correlated data. We show that the characteristic frequency vector that results from the adaptation mechanism reveals the underlying community structure present in the network.

  4. Time Synchronization Strategy Between On-Board Computer and FIMS on STSAT-1

    Directory of Open Access Journals (Sweden)

    Seong Woo Kwak

    2004-06-01

    Full Text Available STSAT-1 was launched on sep. 2003 with the main payload of Far Ultra-violet Imaging Spectrograph(FIMS. The mission of FIMS is to observe universe and aurora. In this paper, we suggest a simple and reliable strategy adopted in STSAT-1 to synchronize time between On-board Computer(OBC and FIMS. For the characteristics of STSAT-1, this strategy is devised to maintain reliability of satellite system and to reduce implementation cost by using minimized electronic circuits. We suggested two methods with different synchronization resolutions to cope with unexpected faults in space. The backup method with low resolution can be activated when the main has some problems.

  5. Low energy plasma observations at synchronous orbit

    International Nuclear Information System (INIS)

    Reasoner, D.L.; Lennartsson, W.

    1977-08-01

    The University of California at San Diego Auroral Particles Experiment on the ATS-6 Satellite in synchronous orbit has detected a low-energy plasma population which is separate and distinct from both the ring current and plasma sheet populations. These observations suggest that this plasma is the outer zone of the plasmasphere. During magnetically active periods, this low energy plasma is often observed flowing sunward. In the dusk sector, enhanced plasma flow is often observed for 1-2 hours prior to the onset of a substorm-associated particle injection. (author)

  6. Social Presence in the Web-based Synchronous Secondary Classroom

    Directory of Open Access Journals (Sweden)

    Eric Nippard

    2007-02-01

    Full Text Available he purpose of the study reported on in this paper was to explore how teachers and students manifest social presence in the web-based synchronous secondary classroom (WBSSC. Data were collected using structured and unstructured observations of twelve online recordings of web-based synchronous classes in the province of Newfoundland and Labrador, Canada. Structured observations were guided by an instrument developed by Rourke, Anderson, Garrison and Archer (2001 for identifying and measuring social presence in an online context. Findings revealed that teachers and students relied on different tools when providing affective, interactive and cohesive responses related to social presence. Manifestations of social presence by the teachers occurred through use of two-way audio whereas students relied on text-based Direct Messaging. Expressions of social presence by the students and teachers occurred most often in a context of digressions that drew attention away from the delivery of content. In addition, students demonstrated social presence using discourse conventions transferred from informal social contexts of instant messaging such as ICQ and MSN. Résumé : L’objet de la présente étude consistait à examiner de quelle façon les enseignants et les étudiants font preuve de présence sociale dans les salles de classe synchrones en ligne du secondaire. Des données ont été recueillies au moyen d’observations structurées et non structurées provenant de douze enregistrements en ligne de classes synchrones accessibles par Internet dans la province de Terre-Neuve et Labrador, Canada. Les observations structurées ont été dirigées au moyen d’un instrument développé par Rourke, Anderson, Garrison, et Archer (2001 afin d’identifier et de mesurer la présence sociale en ligne. Les résultats démontrent que les enseignants et les élèves utilisent des outils différents pour offrir des réponses affectives, interactives et homogènes li

  7. An SDR based AIS receiver for satellites

    DEFF Research Database (Denmark)

    Larsen, Jesper Abildgaard; Mortensen, Hans Peter; Nielsen, Jens Frederik Dalsgaard

    2011-01-01

    For a few years now, there has been a high interest in monitoring the global ship traffic from space. A few satellite, capable of listening for ship borne AIS transponders have already been launched, and soon the AAUSAT3, carrying two different types of AIS receivers will also be launched. One...... of the AIS receivers onboard AAUSAT3 is an SDR based AIS receiver. This paper serves to describe the background of the AIS system, and how the SDR based receiver has been integrated into the AAUSAT3 satellite. Amongst some of the benefits of using an SDR based receiver is, that due to its versatility, new...... detection algorithms are easily deployed, and it is easily adapted the new proposed AIS transmission channels....

  8. Tutorial guide to the tau lepton and close-mass lepton pairs

    International Nuclear Information System (INIS)

    Perl, M.L.

    1988-10-01

    This is a tutorial guide to present knowledge of the tau lepton, to the tau decay mode puzzle, and to present searches for close-mass lepton pairs. The test is minimal; the emphasis is on figures, tables and literature references. It is based on a lecture given at the 1988 International School of Subnuclear Physics: The Super World III. 54 refs., 9 figs., 7 tabs

  9. Getting Started With Oracle SOA Suite 11g R1 - A Hands-On Tutorial

    CERN Document Server

    Buelow, Heidi; Palvankar, Prasen

    2009-01-01

    This fully illustrated step-by-step tutorial is based on proven training material that has been highly praised by hundreds of developers in product training courses given as part of the SOA Suite 11g rollout. You will learn how to build a services-oriente

  10. From DIY tutorials to DIY recipes

    NARCIS (Netherlands)

    Dalton, M.; Desjardins, A.; Wakkary, R.L.

    2014-01-01

    While online DIY (do-it-yourself) tutorials have increasingly gained interest both at CHI and in the DIY and Maker communities, there is not a lot of research concerning the qualities and drawbacks of the current formats used to share DIY knowledge online. Drawing on our current study of DIY

  11. Fuzzy stability and synchronization of hyperchaos systems

    International Nuclear Information System (INIS)

    Wang Junwei; Xiong Xiaohua; Zhao Meichun; Zhang Yanbin

    2008-01-01

    This paper studies stability and synchronization of hyperchaos systems via a fuzzy-model-based control design methodology. First, we utilize a Takagi-Sugeno fuzzy model to represent a hyperchaos system. Second, we design fuzzy-model-based controllers for stability and synchronization of the system, based on so-called 'parallel distributed compensation (PDC)'. Third, we reduce a question of stabilizing and synchronizing hyperchaos systems to linear matrix inequalities (LMI) so that convex programming techniques can solve these LMIs efficiently. Finally, the generalized Lorenz hyperchaos system is employed to illustrate the effectiveness of our designing controller

  12. Assessment of satellite-based precipitation estimates over Paraguay

    Science.gov (United States)

    Oreggioni Weiberlen, Fiorella; Báez Benítez, Julián

    2018-04-01

    Satellite-based precipitation estimates represent a potential alternative source of input data in a plethora of meteorological and hydrological applications, especially in regions characterized by a low density of rain gauge stations. Paraguay provides a good example of a case where the use of satellite-based precipitation could be advantageous. This study aims to evaluate the version 7 of the Tropical Rainfall Measurement Mission Multi-Satellite Precipitation Analysis (TMPA V7; 3B42 V7) and the version 1.0 of the purely satellite-based product of the Climate Prediction Center Morphing Technique (CMORPH RAW) through their comparison with daily in situ precipitation measurements from 1998 to 2012 over Paraguay. The statistical assessment is conducted with several commonly used indexes. Specifically, to evaluate the accuracy of daily precipitation amounts, mean error (ME), root mean square error (RMSE), BIAS, and coefficient of determination (R 2) are used, and to analyze the capability to correctly detect different precipitation intensities, false alarm ratio (FAR), frequency bias index (FBI), and probability of detection (POD) are applied to various rainfall rates (0, 0.1, 0.5, 1, 2, 5, 10, 20, 40, 60, and 80 mm/day). Results indicate that TMPA V7 has a better performance than CMORPH RAW over Paraguay. TMPA V7 has higher accuracy in the estimation of daily rainfall volumes and greater precision in the detection of wet days (> 0 mm/day). However, both satellite products show a lower ability to appropriately detect high intensity precipitation events.

  13. Synchronizing Spatiotemporal Chaos via a Composite Disturbance Observer-Based Sliding Mode Control

    Directory of Open Access Journals (Sweden)

    Congyan Chen

    2014-01-01

    Full Text Available The sliding mode control schemes are investigated to synchronize two spatiotemporal chaotic systems, which are two arrays of a large number of coupled chaotic oscillators. Firstly, sliding mode manifolds with the desired performance are designed. The asymptotic convergence to the origin of the synchronization errors is also proved. However, the terms from parameter fluctuations in equivalent controls are usually impossible to be measured directly. So we regard them as lumped disturbances, but, for practical application, it is difficult to obtain the upper bound of lumped disturbances in advance which often results in a conservative sliding mode control law with large control effort, causing a large amount of chattering. To reduce the chattering and improve the performance of the system, a disturbance observer is designed to estimate the lumped disturbances. A composite synchronization controller that consists of a sliding mode feedback part and a feedforward compensation part based on disturbance observer is developed. The numerical simulation results are presented to show the effectiveness of the proposed methods.

  14. Design and Analysis of simulation experiments : Tutorial

    NARCIS (Netherlands)

    Kleijnen, J.P.C.

    2017-01-01

    This tutorial reviews the design and analysis of simulation experiments. These experiments may have various goals: validation, prediction, sensitivity analysis, optimization (possibly robust), and risk or uncertainty analysis. These goals may be realized through metamodels. Two types of metamodels

  15. Full state hybrid projective synchronization in hyperchaotic systems

    International Nuclear Information System (INIS)

    Chu Yandong; Chang Yingxiang; Zhang Jiangang; Li Xianfeng; An Xinlei

    2009-01-01

    In this letter, we investigate the full state hybrid projective synchronization (FSHPS) which includes complete synchronization, anti-synchronization and projective synchronization as its special items. Based on Lyapunov stability theory a controller can be designed for achieving the FSHPS of hyperchaotic systems. Numerical simulations are provided to verify the effectiveness of the proposed scheme.

  16. The Possibility to Use Genetic Algorithms and Fuzzy Systems in the Development of Tutorial Systems

    Directory of Open Access Journals (Sweden)

    Anca Ioana ANDREESCU

    2006-01-01

    Full Text Available In this paper we are presenting state of the art information methods and techniques that can be applied in the development of efficient tutorial systems and also the possibility to use genetic algorithms and fuzzy systems in the construction of such systems. All this topics have been studied during the development of the research project INFOSOC entitled "Tutorial System based on Eduknowledge for Work Security and Health in SMEs According to the European Union Directives" accomplished by a teaching stuff from the Academy of Economic Studies, Bucharest, in collaboration with the National Institute for Research and Development in Work Security, the National Institute for Small and Middle Enterprises and SC Q’NET International srl.

  17. Critical analysis of a computer-assisted tutorial on ECG interpretation and its ability to determine competency.

    Science.gov (United States)

    Burke, J F; Gnall, E; Umrudden, Z; Kyaw, M; Schick, P K

    2008-01-01

    We developed a computer-based tutorial and a posttest on ECG interpretation for training residents and determining competency. Forty residents, 6 cardiology fellows, and 4 experienced physicians participated. The tutorial emphasized recognition and understanding of abnormal ECG features. Active learning was promoted by asking questions prior to the discussion of ECGs. Interactivity was facilitated by providing rapid and in-depth rationale for correct answers. Responses to questions were recorded and extensively analyzed to determine the quality of questions, baseline knowledge at different levels of training and improvement of grades in posttest. Posttest grades were used to assess improvement and to determine competency. The questions were found to be challenging, fair, appropriate and discriminative. This was important since the quality of Socratic questions is critical for the success of interactive programs. The information on strengths and weakness in baseline knowledge at different levels of training were used to adapt our training program to the needs of residents. The posttest revealed that the tutorial contributed to marked improvement in feature recognition. Competency testing distinguished between residents with outstanding grades and those who needed remediation. The strategy for critical evaluation of our computer program could be applied to any computer-based educational program, regardless of topic.

  18. Constructivist-Based Asynchronous Tutorial to Improve Transfer between Math and Chemistry Domains: Design, Implementation, and Analysis of the Impact of ReMATCH on General Chemistry Course Performance and Confidence

    Science.gov (United States)

    Barker, M. Danielle

    2011-07-01

    The two-year implementation of ReMATCH, a web-based math and problem-solving tutorial, in a traditionally arranged general chemistry classroom at the University of Kansas examined the impact of a designed intervention to assist students with the transfer of their mathematical knowledge to a chemistry context where it could be readily used for quantitative problem solving. The ReMATCH intervention, designed on constructivist-based pedagogies, focused on illuminating the expert-processes of problem solving and transferring knowledge across domains to the novice chemistry. The two implementations of ReMATCH -- once as lab assignments and once lecture assignments -- resulted in very different student responses to the intervention. However, within both, the beneficial effects of sustained ReMATCH-use were visible. In 2006, students who attempted all of the ReMATCH homework assignments were predicted to earn ˜5% higher on their total exam points. The 2007 implementation of ReMATCH demonstrated that students who attempted all of the homework problems and visited at least half of the ReMATCH tutorial pages were predicted to earn ˜8.5% higher on their total exam points. Additionally, use of ReMATCH in 2006 also resulted in increased confidence (as measured by comfort-level) with some of the math-related chemistry topics covered in ReMATCH. In 2007, when only students who attempted all of the ReMATCH problems were considered, it became clear that individuals who were initially less confident in their math-related chemistry skills were more likely to view more of the ReMATCH tutorial pages. When students with lower initial comfort-levels on these topics viewed at least half of the ReMATCH tutorial pages, they were able to compensate for their initially lower levels of confidence and were equally comfortable with most of the math-related chemistry topics by the final survey. Student interactions with and perceptions of ReMATCH showed that student attitudes towards Re

  19. Chaos synchronization using single variable feedback based on backstepping method

    International Nuclear Information System (INIS)

    Zhang Jian; Li Chunguang; Zhang Hongbin; Yu Juebang

    2004-01-01

    In recent years, backstepping method has been developed in the field of nonlinear control, such as controller, observer and output regulation. In this paper, an effective backstepping design is applied to chaos synchronization. There are some advantages in this method for synchronizing chaotic systems, such as (a) the synchronization error is exponential convergent; (b) only one variable information of the master system is needed; (c) it presents a systematic procedure for selecting a proper controller. Numerical simulations for the Chua's circuit and the Roessler system demonstrate that this method is very effective

  20. Adaptive fuzzy observer based synchronization design and secure communications of chaotic systems

    International Nuclear Information System (INIS)

    Hyun, Chang-Ho; Kim, Jae-Hun; Kim, Euntai; Park, Mignon

    2006-01-01

    This paper proposes a synchronization design scheme based on an alternative indirect adaptive fuzzy observer and its application to secure communication of chaotic systems. It is assumed that their states are unmeasurable and their parameters are unknown. Chaotic systems and the structure of the fuzzy observer are represented by the Takagi-Sugeno fuzzy model. Using Lyapunov stability theory, an adaptive law is derived to estimate the unknown parameters and the stability of the proposed system is guaranteed. Through this process, the asymptotic synchronization of chaotic systems is achieved. The proposed observer is applied to secure communications of chaotic systems and some numerical simulation results show the validity of theoretical derivations and the performance of the proposed observer

  1. A signal normalization technique for illumination-based synchronization of 1,000-fps real-time vision sensors in dynamic scenes.

    Science.gov (United States)

    Hou, Lei; Kagami, Shingo; Hashimoto, Koichi

    2010-01-01

    To acquire images of dynamic scenes from multiple points of view simultaneously, the acquisition time of vision sensors should be synchronized. In this paper, an illumination-based synchronization derived from the phase-locked loop (PLL) mechanism based on the signal normalization method is proposed and evaluated. To eliminate the system dependency due to the amplitude fluctuation of the reference illumination, which may be caused by the moving objects or relative positional distance change between the light source and the observed objects, the fluctuant amplitude of the reference signal is normalized framely by the estimated maximum amplitude between the reference signal and its quadrature counterpart to generate a stable synchronization in highly dynamic scenes. Both simulated results and real world experimental results demonstrated successful synchronization result that 1,000-Hz frame rate vision sensors can be successfully synchronized to a LED illumination or its reflected light with satisfactory stability and only 28-μs jitters.

  2. A Signal Normalization Technique for Illumination-Based Synchronization of 1,000-fps Real-Time Vision Sensors in Dynamic Scenes

    Directory of Open Access Journals (Sweden)

    Koichi Hashimoto

    2010-09-01

    Full Text Available To acquire images of dynamic scenes from multiple points of view simultaneously, the acquisition time of vision sensors should be synchronized. In this paper, an illumination-based synchronization derived from the phase-locked loop (PLL mechanism based on the signal normalization method is proposed and evaluated. To eliminate the system dependency due to the amplitude fluctuation of the reference illumination, which may be caused by the moving objects or relative positional distance change between the light source and the observed objects, the fluctuant amplitude of the reference signal is normalized framely by the estimated maximum amplitude between the reference signal and its quadrature counterpart to generate a stable synchronization in highly dynamic scenes. Both simulated results and real world experimental results demonstrated successful synchronization result that 1,000-Hz frame rate vision sensors can be successfully synchronized to a LED illumination or its reflected light with satisfactory stability and only 28-μs jitters.

  3. Synchronization controller design of two coupling permanent magnet synchronous motors system with nonlinear constraints.

    Science.gov (United States)

    Deng, Zhenhua; Shang, Jing; Nian, Xiaohong

    2015-11-01

    In this paper, two coupling permanent magnet synchronous motors system with nonlinear constraints is studied. First of all, the mathematical model of the system is established according to the engineering practices, in which the dynamic model of motor and the nonlinear coupling effect between two motors are considered. In order to keep the two motors synchronization, a synchronization controller based on load observer is designed via cross-coupling idea and interval matrix. Moreover, speed, position and current signals of two motor all are taken as self-feedback signal as well as cross-feedback signal in the proposed controller, which is conducive to improving the dynamical performance and the synchronization performance of the system. The proposed control strategy is verified by simulation via Matlab/Simulink program. The simulation results show that the proposed control method has a better control performance, especially synchronization performance, than that of the conventional PI controller. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  4. Leveraging Technology to Alleviate Student Bottlenecks: The Self-Paced Online Tutorial--Writing (SPOT)

    Science.gov (United States)

    Moore, Scott D.; Sanchez, Rudolph J.; Inoue, Asao B.; Statham, Russel D.; Zelezny, Lynnette; Covino, William A.

    2014-01-01

    The Self-Paced Online Tutorial (SPOT) represents the best kind of innovation because it uses digital technologies wisely and because it is based on well-established theory, research, and practice. Extended education plays a pivotal role in the attainment of the California State University's (CSU) vision of providing a high-quality, affordable, and…

  5. Adaptive H∞ Chaos Anti-synchronization

    International Nuclear Information System (INIS)

    Ahn, Choon Ki

    2010-01-01

    A new adaptive H ∞ anti-synchronization (AHAS) method is proposed for chaotic systems in the presence of unknown parameters and external disturbances. Based on the Lyapunov theory and linear matrix inequality formulation, the AHAS controller with adaptive laws of unknown parameters is derived to not only guarantee adaptive anti-synchronization but also reduce the effect of external disturbances to an H ∞ norm constraint. As an application of the proposed AHAS method, the H ∞ anti-synchronization problem for Genesio–Tesi chaotic systems is investigated. (general)

  6. Inter-satellite calibration of FengYun 3 medium energy electron fluxes with POES electron measurements

    Science.gov (United States)

    Zhang, Yang; Ni, Binbin; Xiang, Zheng; Zhang, Xianguo; Zhang, Xiaoxin; Gu, Xudong; Fu, Song; Cao, Xing; Zou, Zhengyang

    2018-05-01

    We perform an L-shell dependent inter-satellite calibration of FengYun 3 medium energy electron measurements with POES measurements based on rough orbital conjunctions within 5 min × 0.1 L × 0.5 MLT. By comparing electron flux data between the U.S. Polar Orbiting Environmental Satellites (POES) and Chinese sun-synchronous satellites including FY-3B and FY-3C for a whole year of 2014, we attempt to remove less reliable data and evaluate systematic uncertainties associated with the FY-3B and FY-3C datasets, expecting to quantify the inter-satellite calibration factors for the 150-350 keV energy channel at L = 2-7. Compared to the POES data, the FY-3B and FY-3C data generally exhibit a similar trend of electron flux variations but more or less underestimate them within a factor of 5 for the medium electron energy 150-350 keV channel. Good consistency in the flux conjunctions after the inter-calibration procedures gives us certain confidence to generalize our method to calibrate electron flux measurements from various satellite instruments.

  7. NASA Operational Simulator for Small Satellites: Tools for Software Based Validation and Verification of Small Satellites

    Science.gov (United States)

    Grubb, Matt

    2016-01-01

    The NASA Operational Simulator for Small Satellites (NOS3) is a suite of tools to aid in areas such as software development, integration test (IT), mission operations training, verification and validation (VV), and software systems check-out. NOS3 provides a software development environment, a multi-target build system, an operator interface-ground station, dynamics and environment simulations, and software-based hardware models. NOS3 enables the development of flight software (FSW) early in the project life cycle, when access to hardware is typically not available. For small satellites there are extensive lead times on many of the commercial-off-the-shelf (COTS) components as well as limited funding for engineering test units (ETU). Considering the difficulty of providing a hardware test-bed to each developer tester, hardware models are modeled based upon characteristic data or manufacturers data sheets for each individual component. The fidelity of each hardware models is such that FSW executes unaware that physical hardware is not present. This allows binaries to be compiled for both the simulation environment, and the flight computer, without changing the FSW source code. For hardware models that provide data dependent on the environment, such as a GPS receiver or magnetometer, an open-source tool from NASA GSFC (42 Spacecraft Simulation) is used to provide the necessary data. The underlying infrastructure used to transfer messages between FSW and the hardware models can also be used to monitor, intercept, and inject messages, which has proven to be beneficial for VV of larger missions such as James Webb Space Telescope (JWST). As hardware is procured, drivers can be added to the environment to enable hardware-in-the-loop (HWIL) testing. When strict time synchronization is not vital, any number of combinations of hardware components and software-based models can be tested. The open-source operator interface used in NOS3 is COSMOS from Ball Aerospace. For

  8. Radio beacon synchronization in coherent receivers for nanosatellite applications

    OpenAIRE

    Camps Llorente, Daniel; Piera González, Joan

    2017-01-01

    This document presents a study about the Radio beacon synchronization in coherent receivers for nanosatellite applications. First of all, it is studied the history of these nanosatellites and their actual role in the Aerospace industry, considering their low cost compared to bigger satellites and also because of their availability for all types of companies and people (as universities). These nanosatellites have a wide range of applications, and lots of them depend on the imagination of the u...

  9. Target Detection Based on EBPSK Satellite Passive Radar

    Directory of Open Access Journals (Sweden)

    Lu Zeyuan

    2015-05-01

    Full Text Available Passive radar is a topic anti stealth technology with simple structure, and low cost. Radiation source model, signal transmission model, and target detection are the key points of passive radar technology research. The paper analyzes the characteristics of EBPSK signal modulation and target detection method aspect of spaceborne radiant source. By comparison with other satellite navigation and positioning system, the characteristics of EBPSK satellite passive radar system are analyzed. It is proved that the maximum detection range of EBPSK satellite signal can satisfy the needs of the proposed model. In the passive radar model, sparse representation is used to achieve high resolution DOA detection. The comparison with the real target track by simulation demonstrates that effective detection of airborne target using EBPSK satellite passive radar system based on sparse representation is efficient.

  10. Measures of Quantum Synchronization in Continuous Variable Systems

    Science.gov (United States)

    Mari, A.; Farace, A.; Didier, N.; Giovannetti, V.; Fazio, R.

    2013-09-01

    We introduce and characterize two different measures which quantify the level of synchronization of coupled continuous variable quantum systems. The two measures allow us to extend to the quantum domain the notions of complete and phase synchronization. The Heisenberg principle sets a universal bound to complete synchronization. The measure of phase synchronization is, in principle, unbounded; however, in the absence of quantum resources (e.g., squeezing) the synchronization level is bounded below a certain threshold. We elucidate some interesting connections between entanglement and synchronization and, finally, discuss an application based on quantum optomechanical systems.

  11. Analog circuit design a tutorial guide to applications and solutions

    CERN Document Server

    Williams, Jim

    2011-01-01

    * Covers the fundamentals of linear/analog circuit and system design to guide engineers with their design challenges. * Based on the Application Notes of Linear Technology, the foremost designer of high performance analog products, readers will gain practical insights into design techniques and practice. * Broad range of topics, including power management tutorials, switching regulator design, linear regulator design, data conversion, signal conditioning, and high frequency/RF design. * Contributors include the leading lights in analog design, Robert Dobkin, Jim Willia

  12. Satellite Contamination and Materials Outgassing Knowledge base

    Science.gov (United States)

    Minor, Jody L.; Kauffman, William J. (Technical Monitor)

    2001-01-01

    Satellite contamination continues to be a design problem that engineers must take into account when developing new satellites. To help with this issue, NASA's Space Environments and Effects (SEE) Program funded the development of the Satellite Contamination and Materials Outgassing Knowledge base. This engineering tool brings together in one location information about the outgassing properties of aerospace materials based upon ground-testing data, the effects of outgassing that has been observed during flight and measurements of the contamination environment by on-orbit instruments. The knowledge base contains information using the ASTM Standard E- 1559 and also consolidates data from missions using quartz-crystal microbalances (QCM's). The data contained in the knowledge base was shared with NASA by government agencies and industry in the US and international space agencies as well. The term 'knowledgebase' was used because so much information and capability was brought together in one comprehensive engineering design tool. It is the SEE Program's intent to continually add additional material contamination data as it becomes available - creating a dynamic tool whose value to the user is ever increasing. The SEE Program firmly believes that NASA, and ultimately the entire contamination user community, will greatly benefit from this new engineering tool and highly encourages the community to not only use the tool but add data to it as well.

  13. Queueing-Based Synchronization and Entrainment for Synthetic Gene Oscillators

    Science.gov (United States)

    Mather, William; Butzin, Nicholas; Hochendoner, Philip; Ogle, Curtis

    Synthetic gene oscillators have been a major focus of synthetic biology research since the beginning of the field 15 years ago. They have proven to be useful both for biotechnological applications as well as a testing ground to significantly develop our understanding of the design principles behind synthetic and native gene oscillators. In particular, the principles governing synchronization and entrainment of biological oscillators have been explored using a synthetic biology approach. Our work combines experimental and theoretical approaches to specifically investigate how a bottleneck for protein degradation, which is present in most if not all existing synthetic oscillators, can be leveraged to robustly synchronize and entrain biological oscillators. We use both the terminology and mathematical tools of queueing theory to intuitively explain the role of this bottleneck in both synchronization and entrainment, which extends prior work demonstrating the usefulness of queueing theory in synthetic and native gene circuits. We conclude with an investigation of how synchronization and entrainment may be sensitive to the presence of multiple proteolytic pathways in a cell that couple weakly through crosstalk. This work was supported by NSF Grant #1330180.

  14. Tutorial on Online Partial Evaluation

    Directory of Open Access Journals (Sweden)

    William R. Cook

    2011-09-01

    Full Text Available This paper is a short tutorial introduction to online partial evaluation. We show how to write a simple online partial evaluator for a simple, pure, first-order, functional programming language. In particular, we show that the partial evaluator can be derived as a variation on a compositionally defined interpreter. We demonstrate the use of the resulting partial evaluator for program optimization in the context of model-driven development.

  15. A global satellite assisted precipitation climatology

    Science.gov (United States)

    Funk, Christopher C.; Verdin, Andrew P.; Michaelsen, Joel C.; Pedreros, Diego; Husak, Gregory J.; Peterson, P.

    2015-01-01

    Accurate representations of mean climate conditions, especially in areas of complex terrain, are an important part of environmental monitoring systems. As high-resolution satellite monitoring information accumulates with the passage of time, it can be increasingly useful in efforts to better characterize the earth's mean climatology. Current state-of-the-science products rely on complex and sometimes unreliable relationships between elevation and station-based precipitation records, which can result in poor performance in food and water insecure regions with sparse observation networks. These vulnerable areas (like Ethiopia, Afghanistan, or Haiti) are often the critical regions for humanitarian drought monitoring. Here, we show that long period of record geo-synchronous and polar-orbiting satellite observations provide a unique new resource for producing high resolution (0.05°) global precipitation climatologies that perform reasonably well in data sparse regions. Traditionally, global climatologies have been produced by combining station observations and physiographic predictors like latitude, longitude, elevation, and slope. While such approaches can work well, especially in areas with reasonably dense observation networks, the fundamental relationship between physiographic variables and the target climate variables can often be indirect and spatially complex. Infrared and microwave satellite observations, on the other hand, directly monitor the earth's energy emissions. These emissions often correspond physically with the location and intensity of precipitation. We show that these relationships provide a good basis for building global climatologies. We also introduce a new geospatial modeling approach based on moving window regressions and inverse distance weighting interpolation. This approach combines satellite fields, gridded physiographic indicators, and in situ climate normals. The resulting global 0.05° monthly precipitation climatology, the Climate

  16. IMPLEMENTASI MODEL TUTORIAL BERBASIS KOMPUTER FISIOLOGI HEWAN UNTUK MEMBEKALI KEMAMPUAN REKONSTRUKSI KONSEP MAHASISWA CALON GURU BIOLOGI

    Directory of Open Access Journals (Sweden)

    Adeng Slamet

    2015-03-01

    Full Text Available Penelitian ini bertujuan untuk membandingkan model perkuliahan fisiologi hewan yang diharapkan mampu membekali kemampuan rekonstruksi konsep bagi mahasiswa calon guru biologi. Strategi perkuliahan ditempuh melalui implementasi model tutorial berbasis komputer. Sebanyak 80 orang mahasiswa S1 calon guru biologi dibagi ke dalam dua kelompok, 41 mahasiswa mengikuti perkuliahan model tutorial komputer, dan 39 mahasiswa mengikuti perkuliahan konvensional. Kemampuan rekonstruksi konsep diukur dengan membandingkan skor sebelum pembelajaran (pretes dengan setelah implementasi model (postes di antara kedua kelompok belajar. Selain itu, untuk mengungkap pandangan mahasiswa mengenai pengalaman belajarnya, seperangkat angket disebarkan kepada mahasiswa yang mengikuti model perkuliahan.  Efektivitas program perkuliahan dievaluasi dengan tes tertulis bentuk respon terbatas pada mahasiswa yang mengikuti program perkuliahan model tutorial komputer dibandingkan dengan mahasiswa dari kelompok konvensional. Hasil penelitian menunjukkan secara keseluruhan terjadi peningkatan  kemampuan rekonstruksi konsep pada kedua kelompok belajar, namun mahasiswa yang mengikuti perkuliahan model tutorial berbasis komputer menunjukkan peningkatan yang lebih tinggi dibandingkan kelompok mahasiswa peserta perkuliahan konvensional. Mahasiswa menanggapi positif implementasi model tutorial berbasis komputer dalam perkuliahan fisiologi hewan. Dapat disimpulkan bahwa penerapan model tutorial berbasis komputer pada penelitian ini dinyatakan lebih efektif dan mampu  membekali mahasiwa calon guru biologi dalam meningkatkan kemampuan  rekonstruksi konsep.

  17. Three types of generalized synchronization

    Energy Technology Data Exchange (ETDEWEB)

    Yang Junzhong [School of Science, Beijing University of Posts and Telecomunications, Beijing 100876 (China)]. E-mail: jzyang@bupt.edu.cn; Hu Gang [China Center for Advanced Science and Technology (CCAST) (World Laboratory), PO Box 8730, Beijing 100080 (China) and Department of Physics, Beijing Normal University, Beijing 100875 (China)]. E-mail: ganghu@bnu.edu.cn

    2007-02-05

    The roles played by drive and response systems on generalized chaos synchronization (GS) are studied. And the generalized synchronization is classified, based on these roles, to three distinctive types: the passive GS which is mainly determined by the response system and insensitive to the driving signal; the resonant GS where phase synchronization between the drive and response systems is preceding GS; and the interacting GS where both the drive and response have influences on the status of GS. The features of these GS types and the possible changes from one types to others are investigated.

  18. Three types of generalized synchronization

    International Nuclear Information System (INIS)

    Yang Junzhong; Hu Gang

    2007-01-01

    The roles played by drive and response systems on generalized chaos synchronization (GS) are studied. And the generalized synchronization is classified, based on these roles, to three distinctive types: the passive GS which is mainly determined by the response system and insensitive to the driving signal; the resonant GS where phase synchronization between the drive and response systems is preceding GS; and the interacting GS where both the drive and response have influences on the status of GS. The features of these GS types and the possible changes from one types to others are investigated

  19. Review of applications of TLBO algorithm and a tutorial for beginners to solve the unconstrained and constrained optimization problems

    Directory of Open Access Journals (Sweden)

    R. Venkata Rao

    2016-01-01

    Full Text Available The teaching-learning-based optimization (TLBO algorithm is finding a large number of applications in different fields of engineering and science since its introduction in 2011. The major applications are found in electrical engineering, mechanical design, thermal engineering, manufacturing engineering, civil engineering, structural engineering, computer engineering, electronics engineering, physics, chemistry, biotechnology and economics. This paper presents a review of applications of TLBO algorithm and a tutorial for solving the unconstrained and constrained optimization problems. The tutorial is expected to be useful to the beginners.

  20. A Novel Adaptive Observer-Based Control Scheme for Synchronization and Suppression of a Class of Uncertain Chaotic Systems

    International Nuclear Information System (INIS)

    Jing, Wang; Zhen-Yu, Tan; Xi-Kui, Ma; Jin-Feng, Gao

    2009-01-01

    A novel adaptive observer-based control scheme is presented for synchronization and suppression of a class of uncertain chaotic system. First, an adaptive observer based on an orthogonal neural network is designed. Subsequently, the sliding mode controllers via the proposed adaptive observer are proposed for synchronization and suppression of the uncertain chaotic systems. Theoretical analysis and numerical simulation show the effectiveness of the proposed scheme. (general)

  1. Structural damage detection robust against time synchronization errors

    International Nuclear Information System (INIS)

    Yan, Guirong; Dyke, Shirley J

    2010-01-01

    Structural damage detection based on wireless sensor networks can be affected significantly by time synchronization errors among sensors. Precise time synchronization of sensor nodes has been viewed as crucial for addressing this issue. However, precise time synchronization over a long period of time is often impractical in large wireless sensor networks due to two inherent challenges. First, time synchronization needs to be performed periodically, requiring frequent wireless communication among sensors at significant energy cost. Second, significant time synchronization errors may result from node failures which are likely to occur during long-term deployment over civil infrastructures. In this paper, a damage detection approach is proposed that is robust against time synchronization errors in wireless sensor networks. The paper first examines the ways in which time synchronization errors distort identified mode shapes, and then proposes a strategy for reducing distortion in the identified mode shapes. Modified values for these identified mode shapes are then used in conjunction with flexibility-based damage detection methods to localize damage. This alternative approach relaxes the need for frequent sensor synchronization and can tolerate significant time synchronization errors caused by node failures. The proposed approach is successfully demonstrated through numerical simulations and experimental tests in a lab

  2. Handbook of satellite orbits from Kepler to GPS

    CERN Document Server

    Capderou, Michel

    2014-01-01

    Fifty years after Sputnik, artificial satellites have become indispensable monitors in many areas, such as economics, meteorology, telecommunications, navigation and remote sensing. The specific orbits are important for the proper functioning of the satellites. This book discusses the great variety of satellite orbits, both in shape (circular to highly elliptical) and properties (geostationary, Sun-synchronous, etc.). This volume starts with an introduction into geodesy. This is followed by a presentation of the fundamental equations of mechanics to explain and demonstrate the properties for all types of orbits. Numerous examples are included, obtained through IXION software developed by the author. The book also includes an exposition of the historical background that is necessary to help the reader understand the main stages of scientific thought from Kepler to GPS. This book is intended for researchers, teachers and students working in the field of satellite technology. Engineers, geographers and all those...

  3. You Tube Video Genres. Amateur how-to Videos Versus Professional Tutorials

    OpenAIRE

    Andreea Mogoș; Constantin Trofin

    2015-01-01

    In spite of the fact that there is a vast literature on traditional textual and visual genre classifications, the categorization of web content is still a difficult task, because this medium is fluid, unstable and fast-paced on one hand and, on the other hand, the genre classifications are socially constructed through the tagging process and the interactions (commenting, rating, chatting). This paper focuses on YouTube tutorials and aims to compare video tutorials produced by professionals wi...

  4. Adaptive Synchronization of Robotic Sensor Networks

    OpenAIRE

    Yıldırım, Kasım Sinan; Gürcan, Önder

    2014-01-01

    The main focus of recent time synchronization research is developing power-efficient synchronization methods that meet pre-defined accuracy requirements. However, an aspect that has been often overlooked is the high dynamics of the network topology due to the mobility of the nodes. Employing existing flooding-based and peer-to-peer synchronization methods, are networked robots still be able to adapt themselves and self-adjust their logical clocks under mobile network dynamics? In this paper, ...

  5. Synchronization of Rikitake chaotic attractor using active control

    International Nuclear Information System (INIS)

    Vincent, U.E.

    2005-01-01

    Using synchronization technique based on control theory, we design an active controller which enables the synchronization of two identical Rikitake two-disc dynamo systems. Numerical simulations are used to show the robustness of the active control scheme in synchronizing coupled Rikitake dynamical systems. On the sequential application of the active control, transitions from temporary phase locking (TPL) state to complete synchronization state were found

  6. Introducing Multisensor Satellite Radiance-Based Evaluation for Regional Earth System Modeling

    Science.gov (United States)

    Matsui, T.; Santanello, J.; Shi, J. J.; Tao, W.-K.; Wu, D.; Peters-Lidard, C.; Kemp, E.; Chin, M.; Starr, D.; Sekiguchi, M.; hide

    2014-01-01

    Earth System modeling has become more complex, and its evaluation using satellite data has also become more difficult due to model and data diversity. Therefore, the fundamental methodology of using satellite direct measurements with instrumental simulators should be addressed especially for modeling community members lacking a solid background of radiative transfer and scattering theory. This manuscript introduces principles of multisatellite, multisensor radiance-based evaluation methods for a fully coupled regional Earth System model: NASA-Unified Weather Research and Forecasting (NU-WRF) model. We use a NU-WRF case study simulation over West Africa as an example of evaluating aerosol-cloud-precipitation-land processes with various satellite observations. NU-WRF-simulated geophysical parameters are converted to the satellite-observable raw radiance and backscatter under nearly consistent physics assumptions via the multisensor satellite simulator, the Goddard Satellite Data Simulator Unit. We present varied examples of simple yet robust methods that characterize forecast errors and model physics biases through the spatial and statistical interpretation of various satellite raw signals: infrared brightness temperature (Tb) for surface skin temperature and cloud top temperature, microwave Tb for precipitation ice and surface flooding, and radar and lidar backscatter for aerosol-cloud profiling simultaneously. Because raw satellite signals integrate many sources of geophysical information, we demonstrate user-defined thresholds and a simple statistical process to facilitate evaluations, including the infrared-microwave-based cloud types and lidar/radar-based profile classifications.

  7. Synchronization of Estrus in Cattle: A Review

    Directory of Open Access Journals (Sweden)

    R. Islam

    2011-06-01

    Full Text Available Numbers of estrus synchronization programmes are available in cattle based on the use of various hormones like progesterone, prostaglandin F2a and their various combinations with other hormones like estrogen and Gonadotrophin Releasing hormone (GnRH. Selection of appropriate estrus synchronization protocol should be made on the basis of management capabilities and expectations of the farmer. Synchronization of oestrus can be accomplished with the injection of prostaglandin F2a alone, but it needs proper detection of the ovarian status of the cows as prostaglandin F2a is active in only functional corpus luteum in between 8 to 17 days of estrous cycle. Progesterone may reduce fertility up to 14 percent, but short time progesterone exposure (less than 14 days is beneficial. Addition of GnRH in the Progesterone or Prostaglandin based synchronization programme is helpful for more synchrony in estrus as GnRH may be helpful to synchronize the oestrous cycle in delayed pubertal heifers and post partum cows (Post partum anoestrum and further a single, timed artificial insemination is possible with this method. New methods of synchronizing estrus in which the GnRH-PG protocol is preceded by progesterone treatment offer effective synchronization of estrus with high fertility. [Vet. World 2011; 4(3.000: 136-141

  8. Synchronized RACH-less Handover Solution for LTE Heterogeneous Networks

    DEFF Research Database (Denmark)

    Barbera, Simone; Pedersen, Klaus I.; Rosa, Claudio

    2015-01-01

    reductions in the data connectivity interruption time at each handover, no need for random access in the target cell, and reduced overall handover execution time. Laboratory handover measurement results, using commercial LTE equipment, are presented and analyzed to justify the latency benefits......Some of the most recent LTE features require synchronous base stations, and time-synchronized base stations also offer opportunities for improved handover mechanisms by introducing a new synchronized RACH-less handover scheme. The synchronized RACH-less handover solution offers significant...

  9. Multi-spectral band selection for satellite-based systems

    International Nuclear Information System (INIS)

    Clodius, W.B.; Weber, P.G.; Borel, C.C.; Smith, B.W.

    1998-01-01

    The design of satellite based multispectral imaging systems requires the consideration of a number of tradeoffs between cost and performance. The authors have recently been involved in the design and evaluation of a satellite based multispectral sensor operating from the visible through the long wavelength IR. The criteria that led to some of the proposed designs and the modeling used to evaluate and fine tune the designs will both be discussed. These criteria emphasized the use of bands for surface temperature retrieval and the correction of atmospheric effects. The impact of cost estimate changes on the final design will also be discussed

  10. Robust finite-time chaos synchronization of uncertain permanent magnet synchronous motors.

    Science.gov (United States)

    Chen, Qiang; Ren, Xuemei; Na, Jing

    2015-09-01

    In this paper, a robust finite-time chaos synchronization scheme is proposed for two uncertain third-order permanent magnet synchronous motors (PMSMs). The whole synchronization error system is divided into two cascaded subsystems: a first-order subsystem and a second-order subsystem. For the first subsystem, we design a finite-time controller based on the finite-time Lyapunov stability theory. Then, according to the backstepping idea and the adding a power integrator technique, a second finite-time controller is constructed recursively for the second subsystem. No exogenous forces are required in the controllers design but only the direct-axis (d-axis) and the quadrature-axis (q-axis) stator voltages are used as manipulated variables. Comparative simulations are provided to show the effectiveness and superior performance of the proposed method. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  11. Effects of frustration on explosive synchronization

    Science.gov (United States)

    Huang, Xia; Gao, Jian; Sun, Yu-Ting; Zheng, Zhi-Gang; Xu, Can

    2016-12-01

    In this study, we consider the emergence of explosive synchronization in scale-free networks by considering the Kuramoto model of coupled phase oscillators. The natural frequencies of oscillators are assumed to be correlated with their degrees and frustration is included in the system. This assumption can enhance or delay the explosive transition to synchronization. Interestingly, a de-synchronization phenomenon occurs and the type of phase transition is also changed. Furthermore, we provide an analytical treatment based on a star graph, which resembles that obtained in scale-free networks. Finally, a self-consistent approach is implemented to study the de-synchronization regime. Our findings have important implications for controlling synchronization in complex networks because frustration is a controllable parameter in experiments and a discontinuous abrupt phase transition is always dangerous in engineering in the real world.

  12. THE SHORT ROTATION PERIOD OF HI’IAKA, HAUMEA’S LARGEST SATELLITE

    Energy Technology Data Exchange (ETDEWEB)

    Hastings, Danielle M.; Margot, Jean-Luc [University of California, Los Angeles, Department of Earth, Planetary, and Space Sciences, 595 Charles Young Drive East, Los Angeles, CA 90095 (United States); Ragozzine, Darin [Florida Institute of Technology, Department of Physics and Space Sciences, 150 West University Boulevard, Melbourne, FL 32901 (United States); Fabrycky, Daniel C. [Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Burkhart, Luke D.; Holman, Matthew [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fuentes, Cesar [Departamento de Astronomía, Universidad de Chile, Camino El Observatorio 1515, Santiago (Chile); Brown, Michael E., E-mail: dhastings@g.ucla.edu [California Institute of Technology, Division of Geological and Planetary Sciences, MC 150-21, Pasadena, CA 91125 (United States)

    2016-12-01

    Hi’iaka is the larger outer satellite of the dwarf planet Haumea. Using relative photometry from the Hubble Space Telescope and Magellan and a phase dispersion minimization analysis, we have identified the rotation period of Hi’iaka to be ∼9.8 hr (double peaked). This is ∼120 times faster than its orbital period, creating new questions about the formation of this system and possible tidal evolution. The rapid rotation suggests that Hi’iaka could have a significant obliquity and spin precession that could be visible in light curves within a few years. We then turn to an investigation of what we learn about the (currently unclear) formation of the Haumea system and family based on this unexpectedly rapid rotation rate. We explore the importance of the initial semimajor axis and rotation period in tidal evolution theory and find that they strongly influence the time required to despin to synchronous rotation, relevant to understanding a wide variety of satellite and binary systems. We find that despinning tides do not necessarily lead to synchronous spin periods for Hi’iaka, even if it formed near the Roche limit. Therefore, the short rotation period of Hi’iaka does not rule out significant tidal evolution. Hi’iaka’s spin period is also consistent with formation near its current location and spin-up due to Haumea-centric impactors.

  13. Decentralized Traffic Management: A Synchronization-Based Intersection Control --- Extended Version

    OpenAIRE

    Tlig , Mohamed; Buffet , Olivier; Simonin , Olivier

    2014-01-01

    Controlling the vehicle traffic in large networks remains an important challenge in urban environments and transportation systems. Autonomous vehicles are today considered as a promising approach to deal with traffic control. In this paper, we propose a synchronization-based intersection control mechanism to allow the autonomous vehicle-agents to cross without stopping, i.e., in order to avoid congestions (delays) and energy loss. We decentralize the problem by managing the traffic of each in...

  14. Introduction to OAI and harvesting, tutorial 3

    CERN Multimedia

    CERN. Geneva

    2005-01-01

    1. Coverage: - Overview of key Open Archives Initiative (OAI) concepts. - Development of the OAI Protocol for Metadata Harvesting (OAI-PMH). - Non-technical introduction to main underlying technical ideas. - Some considerations regarding implementation of OAI-PMH, with particular focus on harvesting issues. For those who would like an introduction to, or revision of, the main concepts associated with OAI then this session will provide an ideal foundation for the rest of the OAI4 workshop. 2. Audience: Decision-makers, Managers, Technical staff with no previous OAI-PMH knowledge. This is a tutorial for those who may not themselves do hands-on technical implementation, but might make or advise on decisions whether or not to implement particular solutions. They may have staff who are implementers, or may work with them. Technical staff are likely to prefer the technical tutorials, but may want to attend this one if they are at the very early stage of simply requiring background information. 3. At the end of the ...

  15. Using Visual Assessments and Tutorials to Teach Solar System Concepts in Introductory Astronomy

    Science.gov (United States)

    LoPresto, Michael C.

    2010-01-01

    Visual assessments and tutorials are instruments that rely on student construction and/or examination of pictures and/or diagrams rather than multiple choice and/or short answer questions. Being a very visual subject, astronomy lends itself to assessments and tutorials of this type. What follows is a report on the results of the use of visual…

  16. Thermal coupling and effect of subharmonic synchronization in a system of two VO2 based oscillators

    Science.gov (United States)

    Velichko, Andrey; Belyaev, Maksim; Putrolaynen, Vadim; Perminov, Valentin; Pergament, Alexander

    2018-03-01

    We explore a prototype of an oscillatory neural network (ONN) based on vanadium dioxide switching devices. The model system under study represents two oscillators based on thermally coupled VO2 switches. Numerical simulation shows that the effective action radius RTC of coupling depends both on the total energy released during switching and on the average power. It is experimentally and numerically proved that the temperature change ΔT commences almost synchronously with the released power peak and T-coupling reveals itself up to a frequency of about 10 kHz. For the studied switching structure configuration, the RTC value varies over a wide range from 4 to 45 μm, depending on the external circuit capacitance C and resistance Ri, but the variation of Ri is more promising from the practical viewpoint. In the case of a "weak" coupling, synchronization is accompanied by attraction effect and decrease of the main spectra harmonics width. In the case of a "strong" coupling, the number of effects increases, synchronization can occur on subharmonics resulting in multilevel stable synchronization of two oscillators. An advanced algorithm for synchronization efficiency and subharmonic ratio calculation is proposed. It is shown that of the two oscillators the leading one is that with a higher main frequency, and, in addition, the frequency stabilization effect is observed. Also, in the case of a strong thermal coupling, the limit of the supply current parameters, for which the oscillations exist, expands by ∼10%. The obtained results have a universal character and open up a new kind of coupling in ONNs, namely, T-coupling, which allows for easy transition from 2D to 3D integration. The effect of subharmonic synchronization hold promise for application in classification and pattern recognition.

  17. L'ajuda tutorial en els MOOCs: un nou enfocament en l'acció tutorial

    Directory of Open Access Journals (Sweden)

    Rosario Medina-Salguero

    2013-12-01

    Full Text Available En el present treball s'expon un analisis de l'accio tutorial en una nova modalitat d'ensenyança-aprenentage, els MOOCS. Per a açò, hem portat a veta un estudi de material documental que permet reconstruir els acontenyiments que estan succeint en l'actualitat en els MOOCS. Els resultats mos indiquen com se configura esta nova tendencia d'aprenentage a nivell internacional i nacional i com s'establix l'ajuda pedagogica en els MOOCS.

  18. Dynamic Shift Coordinated Control Based on Motor Active Speed Synchronization with the New Hybrid System

    Directory of Open Access Journals (Sweden)

    Ting Yan

    2017-01-01

    Full Text Available Considering the inherent disadvantages that severely affect driving comfortability during the shift process in HEVs, a dynamic shift coordinated control based on motor active speed synchronization is proposed to improve shift quality by reduction of shift vibration. The whole control scheme is comprised of three phases, preparatory phase, speed regulation phase, and synchronization phase, which are implemented consecutively in order. The key to inhibiting impact and jerk depends on the speed regulation phase, where motor active speed synchronization is utilized to reach the minimum speed difference between the two ends of synchronizer. A new hybrid system with superior performances is applied to present the validity of the adopted control algorithm during upshift or downshift, which can represent planetary gear system and conventional AMT shift procedure, respectively. Bench test, simulation, and road test results show that, compared with other methods, the proposed dynamic coordinated control can achieve shifting control in real time to effectively improve gear-shift comfort and shorten power interruption transients, with robustness in both conventional AMT and planetary gear train.

  19. Tutorial: Speech Assessment for Multilingual Children Who Do Not Speak the Same Language(s) as the Speech-Language Pathologist.

    Science.gov (United States)

    McLeod, Sharynne; Verdon, Sarah

    2017-08-15

    The aim of this tutorial is to support speech-language pathologists (SLPs) undertaking assessments of multilingual children with suspected speech sound disorders, particularly children who speak languages that are not shared with their SLP. The tutorial was written by the International Expert Panel on Multilingual Children's Speech, which comprises 46 researchers (SLPs, linguists, phoneticians, and speech scientists) who have worked in 43 countries and used 27 languages in professional practice. Seventeen panel members met for a 1-day workshop to identify key points for inclusion in the tutorial, 26 panel members contributed to writing this tutorial, and 34 members contributed to revising this tutorial online (some members contributed to more than 1 task). This tutorial draws on international research evidence and professional expertise to provide a comprehensive overview of working with multilingual children with suspected speech sound disorders. This overview addresses referral, case history, assessment, analysis, diagnosis, and goal setting and the SLP's cultural competence and preparation for working with interpreters and multicultural support workers and dealing with organizational and government barriers to and facilitators of culturally competent practice. The issues raised in this tutorial are applied in a hypothetical case study of an English-speaking SLP's assessment of a multilingual Cantonese- and English-speaking 4-year-old boy. Resources are listed throughout the tutorial.

  20. Effects of personality traits on collaborative performance in problem-based learning tutorials.

    Science.gov (United States)

    Jang, Hye Won; Park, Seung Won

    2016-12-01

    To examine the relationship between students' collaborative performance in a problem-based learning (PBL) environment and their personality traits. Methods:This retrospective, cross-sectional study was conducted using student data of a PBL program between 2013 and 2014 at Sungkyunkwan University School of Medicine, Seoul, South Korea. Eighty students were included in the study. Student data from the Temperament and Character Inventory were used as a measure of their personality traits. Peer evaluation scores during PBL were used as a measure of students' collaborative performance. Results: Simple regression analyses indicated that participation was negatively related to harm avoidance and positively related to persistence, whereas preparedness for the group work was negatively related to reward dependence. On multiple regression analyses, low reward dependence remained a significant predictor of preparedness. Grade-point average (GPA)  was negatively associated with novelty seeking and cooperativeness and was positively associated with persistence.  Conclusion: Medical students who are less dependent on social reward are more likely to complete assigned independent work to prepare for the PBL tutorials. The findings of this study can help educators better understand and support medical students who are at risk of struggling in collaborative learning environments.

  1. Satellite based wind resource assessment over the South China Sea

    DEFF Research Database (Denmark)

    Badger, Merete; Astrup, Poul; Hasager, Charlotte Bay

    2014-01-01

    variations are clearly visible across the domain; for instance sheltering effects caused by the land masses. The satellite based wind resource maps have two shortcomings. One is the lack of information at the higher vertical levels where wind turbines operate. The other is the limited number of overlapping...... years of WRF data – specifically the parameters heat flux, air temperature, and friction velocity – are used to calculate a long-term correction for atmospheric stability effects. The stability correction is applied to the satellite based wind resource maps together with a vertical wind profile...... from satellite synthetic aperture radar (SAR) data are particularly suitable for offshore wind energy applications because they offer a spatial resolution up to 500 m and include coastal seas. In this presentation, satellite wind maps are used in combination with mast observations and numerical...

  2. Statistical Tutorial | Center for Cancer Research

    Science.gov (United States)

    Recent advances in cancer biology have resulted in the need for increased statistical analysis of research data.  ST is designed as a follow up to Statistical Analysis of Research Data (SARD) held in April 2018.  The tutorial will apply the general principles of statistical analysis of research data including descriptive statistics, z- and t-tests of means and mean

  3. Exponential lag function projective synchronization of memristor-based multidirectional associative memory neural networks via hybrid control

    Science.gov (United States)

    Yuan, Manman; Wang, Weiping; Luo, Xiong; Li, Lixiang; Kurths, Jürgen; Wang, Xiao

    2018-03-01

    This paper is concerned with the exponential lag function projective synchronization of memristive multidirectional associative memory neural networks (MMAMNNs). First, we propose a new model of MMAMNNs with mixed time-varying delays. In the proposed approach, the mixed delays include time-varying discrete delays and distributed time delays. Second, we design two kinds of hybrid controllers. Traditional control methods lack the capability of reflecting variable synaptic weights. In this paper, the controllers are carefully designed to confirm the process of different types of synchronization in the MMAMNNs. Third, sufficient criteria guaranteeing the synchronization of system are derived based on the derive-response concept. Finally, the effectiveness of the proposed mechanism is validated with numerical experiments.

  4. Effectiveness of interactive tutorials in promoting "which-path" information reasoning in advanced quantum mechanics

    Science.gov (United States)

    Maries, Alexandru; Sayer, Ryan; Singh, Chandralekha

    2017-12-01

    Research suggests that introductory physics students often have difficulty using a concept in contexts different from the ones in which they learned it without explicit guidance to help them make the connection between the different contexts. We have been investigating advanced students' learning of quantum mechanics concepts and have developed interactive tutorials which strive to help students learn these concepts. Two such tutorials, focused on the Mach-Zehnder interferometer (MZI) and the double-slit experiment (DSE), help students learn how to use the concept of "which-path" information to reason about the presence or absence of interference in these two experiments in different situations. After working on a pretest that asked students to predict interference in the MZI with single photons and polarizers of various orientations placed in one or both paths of the MZI, students worked on the MZI tutorial which, among other things, guided them to reason in terms of which-path information in order to predict interference in similar situations. We investigated the extent to which students were able to use reasoning related to which-path information learned in the MZI tutorial to answer analogous questions on the DSE (before working on the DSE tutorial). After students worked on the DSE pretest they worked on a DSE tutorial in which they learned to use the concept of which-path information to answer questions about interference in the DSE with single particles with mass sent through the two slits and a monochromatic lamp placed between the slits and the screen. We investigated if this additional exposure to the concept of which-path information promoted improved learning and performance on the DSE questions with single photons and polarizers placed after one or both slits. We find evidence that both tutorials promoted which-path information reasoning and helped students use this reasoning appropriately in contexts different from the ones in which they had learned

  5. The MAGIC of Web Tutorials: How One Library (Re)Focused Its Delivery of Online Learning Objects on Users

    Science.gov (United States)

    Hess, Amanda Nichols

    2013-01-01

    Oakland University (OU) Libraries undertook an assessment of how to leverage its resources to make online tutorials more focused on users' needs. A multi-part assessment process reconsidered Web tutorials offerings through the lenses of faculty and staff feedback, literature review, and an analysis of other universities' online tutorial offerings.…

  6. Online Bioinformatics Tutorials | Office of Cancer Genomics

    Science.gov (United States)

    Bioinformatics is a scientific discipline that applies computer science and information technology to help understand biological processes. The NIH provides a list of free online bioinformatics tutorials, either generated by the NIH Library or other institutes, which includes introductory lectures and "how to" videos on using various tools.

  7. Analysis of the partially filled viscous ring damper. [application as nutation damper for spinning satellite

    Science.gov (United States)

    Alfriend, K. T.

    1973-01-01

    A ring partially filled with a viscous fluid has been analyzed as a nutation damper for a spinning satellite. The fluid has been modelled as a rigid slug of finite length moving in a tube and resisted by a linear viscous force. It is shown that there are two distinct modes of motion, called the spin synchronous mode and the nutation synchronous mode. Time constants for each mode are obtained for both the symmetric and asymmetric satellite. The effects of a stop in the tube and an offset of the ring from the spin axis are also investigated. An analysis of test results is also given including a determination of the effect of gravity on the time constants in the two modes.

  8. Satellites

    International Nuclear Information System (INIS)

    Burns, J.A.; Matthews, M.S.

    1986-01-01

    The present work is based on a conference: Natural Satellites, Colloquium 77 of the IAU, held at Cornell University from July 5 to 9, 1983. Attention is given to the background and origins of satellites, protosatellite swarms, the tectonics of icy satellites, the physical characteristics of satellite surfaces, and the interactions of planetary magnetospheres with icy satellite surfaces. Other topics include the surface composition of natural satellites, the cratering of planetary satellites, the moon, Io, and Europa. Consideration is also given to Ganymede and Callisto, the satellites of Saturn, small satellites, satellites of Uranus and Neptune, and the Pluto-Charon system

  9. The Development of Synchronization Function for Triple Redundancy System Based on SCADE

    Directory of Open Access Journals (Sweden)

    Moupeng

    2015-07-01

    Full Text Available Redundancy technique is an effective approach to improve the reliability and security of flight control system, synchronization function of redundancy system is the key technology of redundancy management. The flight control computer synchronization model is developed by graphical modeling method in the SCADE development environment, the automatic code generation technology is used to generate high level reliable embedded real-time code for synchronization function, omitting the code test process, shorten the development cycle. In the practical application, the program can accomplish the functional synchronization, and lay a well foundation for the redundancy system.

  10. Phase synchronization based minimum spanning trees for analysis of financial time series with nonlinear correlations

    Science.gov (United States)

    Radhakrishnan, Srinivasan; Duvvuru, Arjun; Sultornsanee, Sivarit; Kamarthi, Sagar

    2016-02-01

    The cross correlation coefficient has been widely applied in financial time series analysis, in specific, for understanding chaotic behaviour in terms of stock price and index movements during crisis periods. To better understand time series correlation dynamics, the cross correlation matrices are represented as networks, in which a node stands for an individual time series and a link indicates cross correlation between a pair of nodes. These networks are converted into simpler trees using different schemes. In this context, Minimum Spanning Trees (MST) are the most favoured tree structures because of their ability to preserve all the nodes and thereby retain essential information imbued in the network. Although cross correlations underlying MSTs capture essential information, they do not faithfully capture dynamic behaviour embedded in the time series data of financial systems because cross correlation is a reliable measure only if the relationship between the time series is linear. To address the issue, this work investigates a new measure called phase synchronization (PS) for establishing correlations among different time series which relate to one another, linearly or nonlinearly. In this approach the strength of a link between a pair of time series (nodes) is determined by the level of phase synchronization between them. We compare the performance of phase synchronization based MST with cross correlation based MST along selected network measures across temporal frame that includes economically good and crisis periods. We observe agreement in the directionality of the results across these two methods. They show similar trends, upward or downward, when comparing selected network measures. Though both the methods give similar trends, the phase synchronization based MST is a more reliable representation of the dynamic behaviour of financial systems than the cross correlation based MST because of the former's ability to quantify nonlinear relationships among time

  11. Space environment monitoring by low-altitude operational satellites

    International Nuclear Information System (INIS)

    Kroehl, H.W.

    1982-01-01

    The primary task of the Defense Meteorological Satellite Program (DMSP) is the acquisition of meteorological data in the visual and infrared spectral regions. The Air Weather Service operates two satellites in low-altitude, sun-synchronous, polar orbits at 850 km altitude, 98.7 deg inclination, 101.5 minute period and dawn-dusk or noon-midnight equatorial crossing times. Special DMSP sensors of interest to the space science community are the precipitating electron spectrometer, the terrestrial noise receiver, and the topside ionosphere plasma monitor. Data from low-altitude, meteorological satellites can be used to build empirical models of precipitating electron characteristics of the auroral zone and polar cap. The Tiros-NOAA satellite program complements the DMSP program. The orbital elements are the same as DMSP's, except for the times of equatorial crossing, and the tilt of the orbital plane. The Tiros-NOAA program meets the civilian community's needs for meteorological data as the DMSP program does for the military

  12. Robust synchronization of delayed neural networks based on adaptive control and parameters identification

    International Nuclear Information System (INIS)

    Zhou Jin; Chen Tianping; Xiang Lan

    2006-01-01

    This paper investigates synchronization dynamics of delayed neural networks with all the parameters unknown. By combining the adaptive control and linear feedback with the updated law, some simple yet generic criteria for determining the robust synchronization based on the parameters identification of uncertain chaotic delayed neural networks are derived by using the invariance principle of functional differential equations. It is shown that the approaches developed here further extend the ideas and techniques presented in recent literature, and they are also simple to implement in practice. Furthermore, the theoretical results are applied to a typical chaotic delayed Hopfied neural networks, and numerical simulation also demonstrate the effectiveness and feasibility of the proposed technique

  13. Space-based solar power conversion and delivery systems study. Volume 2: Engineering analysis of orbital systems

    Science.gov (United States)

    1976-01-01

    Program plans, schedules, and costs are determined for a synchronous orbit-based power generation and relay system. Requirements for the satellite solar power station (SSPS) and the power relay satellite (PRS) are explored. Engineering analysis of large solar arrays, flight mechanics and control, transportation, assembly and maintenance, and microwave transmission are included.

  14. Using Active-Learning Pedagogy to Develop Essay-Writing Skills in Introductory Political Theory Tutorials

    Science.gov (United States)

    Murphy, Michael P. A.

    2017-01-01

    Building on prior research into active learning pedagogy in political science, I discuss the development of a new active learning strategy called the "thesis-building carousel," designed for use in political theory tutorials. This use of active learning pedagogy in a graduate student-led political theory tutorial represents the overlap…

  15. Difference-based Model Synchronization in an Industrial MDD Process

    DEFF Research Database (Denmark)

    Könemann, Patrick; Kindler, Ekkart; Unland, Ludger

    2009-01-01

    Models play a central role in model-driven software engineering. There are different kinds of models during the development process, which are related to each other and change over time. Therefore, it is difficult to keep the different models consistent with each other. Consistency of different m...... model versions, and for synchronizing other types of models. The main concern is to apply our concepts to an industrial process, in particular keeping usability and performance in mind. Keyword: Model Differencing, Model Merging, Model Synchronization...

  16. Adaptive synchronization of Rossler system with uncertain parameters

    International Nuclear Information System (INIS)

    Park, Ju H.

    2005-01-01

    This article addresses control for the chaos synchronization of Rossler systems with three uncertain parameters. Based on the Lyapunov stability theory, an adaptive control law is derived to make the states of two identical Rossler systems asymptotically synchronized. A numerical simulations is presented to show the effectiveness of the proposed chaos synchronization scheme

  17. LIVE AUTHORITY IN THE CLASSROOM IN VIDEO CONFERENCE-BASED SYNCHRONOUS DISTANCE EDUCATION: The Teaching Assistant

    Directory of Open Access Journals (Sweden)

    Hasan KARAL

    2010-07-01

    Full Text Available The aim of this study was to define the role of the assistant in a classroom environment where students are taught using video conference-based synchronous distance education. Qualitative research approach was adopted and, among purposeful sampling methods, criterion sampling method was preferred in the scope of the study. The study was carried out during the spring semester of the 2008-2009 academic years. A teaching assistant and a total of 9 sophomore or senior students from the Department of City and Regional Development, Faculty of Architecture, Karadeniz Technical University, participated as subjects. The students included in the study sampling were taking lessons from the Middle East Technical University on the basis of synchronous distance education. Among the qualitative research methods, case study method was used and the study data were obtained from the semi-structured interview and observation results. Study data were analyzed with descriptive analysis methods. Data obtained at the end of the study were found to support the suggestion that there should be an authority in the video conference-based synchronous distance education. Findings obtained during the interviews made with the students revealed that some of the teacher’s classroom management related responsibilities are transferred to the assistant present in the classroom during the synchronous distance education. It was concluded at the end of the interviews that a teaching assistant’s presence should be obligatory in the undergraduate synchronous distance classroom environment. However, it was also concluded that there may not be any need for an authority in the classroom environment at the postgraduate education level due to the profile and expectations of the student, which differ from those of students at lower educational levels.

  18. Supporting Interactive Teaching Methods at the New Faculty Workshop with Astronomy Lecture-Tutorials

    Science.gov (United States)

    Slater, T. F.; Brissenden, G.; Duestua, S.; Prather, E. E.

    2004-05-01

    Ongoing research by the Conceptual Astronomy and Physics Education Research (CAPER) Team at the University of Arizona Steward Observatory suggests that, although faculty realize that lecture-based instruction is ineffective for many students, they are not aware of what interactive teaching strategies are available, particularly for large enrollment courses. A major emphasis of the AAPT/AAS New Faculty Workshop was to introduce faculty to effective active-learning strategies based on an understanding of how people learn. Faculty were introduced to think-pair-share methods where students work together to explain difficult concepts to each other. Faculty were also introduced to authentic assessment strategies that go beyond using traditional multiple-choice tests. In particular, faculty were introduced to Lecture-Tutorials for Introductory Astronomy. The Lecture-Tutorials are instructional materials intended for use with collaborative student learning groups and are designed specifically to be easily integrated into existing courses centered on conventional lectures and do not require any outside equipment or a drastic course revision for implementation. The materials are based on research into student beliefs and reasoning difficulties and use effective instructional strategies that center on student learning. Each workshop presentation was complimented by a follow-up small group discussion session.

  19. Generation of Tutorial Dialogues: Discourse Strategies for Active Learning

    National Research Council Canada - National Science Library

    Evans, Martha

    1998-01-01

    With the support of the Cognitive Science Program of ONR, we are developing the capability to generate complex natural language tutorial dialogues for an intelligent tutoring system designed to help...

  20. Building a satellite climate diagnostics data base for real-time climate monitoring

    International Nuclear Information System (INIS)

    Ropelewski, C.F.

    1991-01-01

    The paper discusses the development of a data base, the Satellite Climate Diagnostic Data Base (SCDDB), for real time operational climate monitoring utilizing current satellite data. Special attention is given to the satellite-derived quantities useful for monitoring global climate changes, the requirements of SCDDB, and the use of conventional meteorological data and model assimilated data in developing the SCDDB. Examples of prototype SCDDB products are presented. 10 refs

  1. Guidelines for Effective TAP (Translation for Academic Purposes Tutorial Courses

    Directory of Open Access Journals (Sweden)

    Elham Yazdanmehr

    2014-03-01

    Full Text Available An increasing need is felt by the university students, especially at Master’s or PhD level, to get a satisfactory command of English so as to manage great amounts of technical materials and articles published internationally. Public and private language institutions, however, have not responded to this need properly specially in non-English speaking countries including Iran. Therefore, the only way left for the students is to demand tutorial sessions which are rare, and if existing, of diverse questionable quality. There seems to be a dearth of base-line or criteria released in any form to define and guide the tutors’ approach and techniques which can be in accordance with university students’ needs and purposes. Aiming to fill this gap, the present paper attempts to be a pioneering research in the realm of TAP (Translation for Academic Purposes tutorial courses and intends to provide guidelines on text selection, role allocation, timing, rate, assignments and other relevant issues in this area. The guidelines are provided based on a post facto case study carried out by one of the authors which created the motive for this research and may further clarify the significance of the issues discussed. The recommended guidelines consist of 5 basic elements and 3 principles. It was discovered, and is expected for others as well, that following these guidelines helps to manage a TAP course in the best and most fruitful way with the least time wasted and with satisfactory result.

  2. Automated problem generation in Learning Management Systems: a tutorial

    Directory of Open Access Journals (Sweden)

    Jaime Romero

    2016-07-01

    Full Text Available The benefits of solving problems have been widely acknowledged by literature. Its implementation in e–learning platforms can make easier its management and the learning process itself. However, its implementation can also become a very time–consuming task, particularly when the number of problems to generate is high. In this tutorial we describe a methodology that we have developed aiming to alleviate the workload of producing a great deal of problems in Moodle for an undergraduate business course. This methodology follows a six-step process and allows evaluating student’s skills in problem solving, minimizes plagiarism behaviors and provides immediate feedback. We expect this tutorial encourage other educators to apply our six steps process, thus benefiting themselves and their students of its advantages.

  3. A near real-time satellite-based global drought climate data record

    International Nuclear Information System (INIS)

    AghaKouchak, Amir; Nakhjiri, Navid

    2012-01-01

    Reliable drought monitoring requires long-term and continuous precipitation data. High resolution satellite measurements provide valuable precipitation information on a quasi-global scale. However, their short lengths of records limit their applications in drought monitoring. In addition to this limitation, long-term low resolution satellite-based gauge-adjusted data sets such as the Global Precipitation Climatology Project (GPCP) one are not available in near real-time form for timely drought monitoring. This study bridges the gap between low resolution long-term satellite gauge-adjusted data and the emerging high resolution satellite precipitation data sets to create a long-term climate data record of droughts. To accomplish this, a Bayesian correction algorithm is used to combine GPCP data with real-time satellite precipitation data sets for drought monitoring and analysis. The results showed that the combined data sets after the Bayesian correction were a significant improvement compared to the uncorrected data. Furthermore, several recent major droughts such as the 2011 Texas, 2010 Amazon and 2010 Horn of Africa droughts were detected in the combined real-time and long-term satellite observations. This highlights the potential application of satellite precipitation data for regional to global drought monitoring. The final product is a real-time data-driven satellite-based standardized precipitation index that can be used for drought monitoring especially over remote and/or ungauged regions. (letter)

  4. Staying on Top of Your Game and Scoring Big with Adobe Presenter Multimedia Tutorials

    Science.gov (United States)

    Koury, Regina; Francis, Marcia J.; Gray, Catherine J.; Jardine, Spencer J.; Guo, Ruiling

    2010-01-01

    In order to reach distance students in times of financial uncertainty, librarians must be creative. While much has been written about Camtasia, Captivate and Jing tutorial software, Adobe Presenter, a Microsoft PowerPoint plug-in, has not been discussed. This article describes how our library team created multimedia tutorial projects at Idaho…

  5. Identifying Typhoon Tracks based on Event Synchronization derived Spatially Embedded Climate Networks

    Science.gov (United States)

    Ozturk, Ugur; Marwan, Norbert; Kurths, Jürgen

    2017-04-01

    Complex networks are commonly used for investigating spatiotemporal dynamics of complex systems, e.g. extreme rainfall. Especially directed networks are very effective tools in identifying climatic patterns on spatially embedded networks. They can capture the network flux, so as the principal dynamics of spreading significant phenomena. Network measures, such as network divergence, bare the source-receptor relation of the directed networks. However, it is still a challenge how to catch fast evolving atmospheric events, i.e. typhoons. In this study, we propose a new technique, namely Radial Ranks, to detect the general pattern of typhoons forward direction based on the strength parameter of the event synchronization over Japan. We suggest to subset a circular zone of high correlation around the selected grid based on the strength parameter. Radial sums of the strength parameter along vectors within this zone, radial ranks are measured for potential directions, which allows us to trace the network flux over long distances. We employed also the delay parameter of event synchronization to identify and separate the frontal storms' and typhoons' individual behaviors.

  6. Geometric Aspects of Ground Augmentation of Satellite Networks for the Needs of Deformation Monitoring

    Science.gov (United States)

    Protaziuk, Elżbieta

    2016-06-01

    Satellite measurements become competitive in many tasks of engineering surveys, however, in many requiring applications possibilities to apply such solutions are still limited. The possibility to widely apply satellite technologies for displacements measurements is related with new challenges; the most important of them relate to increasing requirements concerning the accuracy, reliability and continuity of results of position determination. One of the solutions is a ground augmentation of satellite network, which intention is to improve precision of positioning, ensure comparable accuracy of coordinates and reduce precision fluctuations over time. The need for augmentation of GNSS is particularly significant in situations: where the visibility of satellites is poor because of terrain obstacles, when the determined position is not precise enough or a satellites constellation does not allow for reliable positioning. Ground based source/sources of satellite signal placed at a ground, called pseudosatellites, or pseudolites were intensively investigated during the last two decades and finally were developed into groundbased, time-synchronized transceivers, that can transmit and receive a proprietary positioning signal. The paper presents geometric aspects of the ground based augmentation of the satellite networks using various quality measures of positioning geometry, which depends on access to the constellation of satellites and the conditions of the observation environment. The issue of minimizing these measures is the key problem that allows to obtain the position with high accuracy. For this purpose, the use of an error ellipsoid is proposed and compared with an error ellipse. The paper also describes the results of preliminary accuracy analysis obtained at test area and a comparison of various measures of the quality of positioning geometry.

  7. An Audit of the Effectiveness of Large Group Neurology Tutorials for Irish Undergraduate Medical Students

    LENUS (Irish Health Repository)

    Kearney, H

    2016-07-01

    The aim of this audit was to determine the effectiveness of large group tutorials for teaching neurology to medical students. Students were asked to complete a questionnaire rating their confidence on a ten point Likert scale in a number of domains in the undergraduate education guidelines from the Association of British Neurologists (ABN). We then arranged a series of interactive large group tutorials for the class and repeated the questionnaire one month after teaching. In the three core domains of neurological: history taking, examination and differential diagnosis, none of the students rated their confidence as nine or ten out of ten prior to teaching. This increased to 6% for history taking, 12 % in examination and 25% for differential diagnosis after eight weeks of tutorials. This audit demonstrates that in our centre, large group tutorials were an effective means of teaching, as measured by the ABN guidelines in undergraduate neurology.

  8. Development of sub-100 femtosecond timing and synchronization system.

    Science.gov (United States)

    Lin, Zhenyang; Du, Yingchao; Yang, Jin; Xu, Yilun; Yan, Lixin; Huang, Wenhui; Tang, Chuanxiang; Huang, Gang; Du, Qiang; Doolittle, Lawrence; Wilcox, Russell; Byrd, John

    2018-01-01

    The precise timing and synchronization system is an essential part for the ultra-fast electron and X-ray sources based on the photocathode injector where strict synchronization among RF, laser, and beams are required. In this paper, we present an integrated sub-100 femtosecond timing and synchronization system developed and demonstrated recently in Tsinghua University based on the collaboration with Lawrence Berkeley National Lab. The timing and synchronization system includes the fiber-based CW carrier phase reference distribution system for delivering stabilized RF phase reference to multiple receiver clients, the Low Level RF (LLRF) control system to monitor and generate the phase and amplitude controllable pulse RF signal, and the laser-RF synchronization system for high precision synchronization between optical and RF signals. Each subsystem is characterized by its blocking structure and is also expansible. A novel asymmetric calibration sideband signal method was proposed for eliminating the non-linear distortion in the optical synchronization process. According to offline and online tests, the system can deliver a stable signal to each client and suppress the drift and jitter of the RF signal for the accelerator and the laser oscillator to less than 100 fs RMS (∼0.1° in 2856 MHz frequency). Moreover, a demo system with a LLRF client and a laser-RF synchronization client is deployed and operated successfully at the Tsinghua Thomson scattering X-ray source. The beam-based jitter measurement experiments have been conducted to evaluate the overall performance of the system, and the jitter sources are discussed.

  9. Assessing satellite-based start-of-season trends in the US High Plains

    International Nuclear Information System (INIS)

    Lin, X; Sassenrath, G F; Hubbard, K G; Mahmood, R

    2014-01-01

    To adequately assess the effects of global warming it is necessary to address trends and impacts at the local level. This study examines phenological changes in the start-of-season (SOS) derived from satellite observations from 1982–2008 in the US High Plains region. The surface climate-based SOS was also evaluated. The averaged profiles of SOS from 37° to 49°N latitude by satellite- and climate-based methods were in reasonable agreement, especially for areas where croplands were masked out and an additional frost date threshold was adopted. The statistically significant trends of satellite-based SOS show a later spring arrival ranging from 0.1 to 4.9 days decade −1 over nine Level III ecoregions. We found the croplands generally exhibited larger trends (later arrival) than the non-croplands. The area-averaged satellite-based SOS for non-croplands (i.e. mostly grasslands) showed no significant trends. We examined the trends of temperatures, precipitation, and standardized precipitation index (SPI), as well as the strength of correlation between the satellite-based SOS and these climatic drivers. Our results indicate that satellite-based SOS trends are spatially and primarily related to annual maximum normalized difference vegetation index (NDVI, mostly in summertime) and/or annual minimum NDVI (mostly in wintertime) and these trends showed the best correlation with six-month SPI over the period 1982–2008 in the US High Plains region. (letter)

  10. Communicating via robust synchronization of chaotic lasers

    International Nuclear Information System (INIS)

    Lopez-Gutierrez, R.M.; Posadas-Castillo, C.; Lopez-Mancilla, D.; Cruz-Hernandez, C.

    2009-01-01

    In this paper, the robust synchronization problem for coupled chaotic Nd:YAG lasers is addressed. We resort to complex systems theory to achieve chaos synchronization. Based on stability theory, it is shown that the state trajectories of the perturbed error synchronization are ultimately bounded, provided the unperturbed synchronization error system is exponentially stable, and some conditions on the bounds of the perturbation terms are satisfied. So that, encoding, transmission, and decoding in chaotic optical communications are presented. We analyze the transmission and recovery of encrypted information when parameter mismatches are considered. Computer simulations are provided to show the effectiveness of this robustness synchronization property, we present the encrypted transmission of image messages, and we show that, the transmitted image is faithfully recovered.

  11. Communicating via robust synchronization of chaotic lasers

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Gutierrez, R.M. [Engineering Faculty, Baja California Autonomous University (UABC), Km. 103 Carret. Tij-Ens., 22860 Ensenada, B.C. (Mexico); Posadas-Castillo, C. [Engineering Faculty, Baja California Autonomous University (UABC), Km. 103 Carret. Tij-Ens., 22860 Ensenada, B.C. (Mexico); FIME, Autonomous University of Nuevo Leon (UANL), Pedro de Alba, S.N., Cd. Universitaria, San Nicolas de los Garza, NL (Mexico); Lopez-Mancilla, D. [Departamento de Ciencias Exactas y Tecnologicas, Centro Universitario de los Lagos, Universidad de Guadalajara (CULagos-UdeG), Enrique Diaz de Leon s/n, 47460 Lagos de Moreno, Jal. (Mexico); Cruz-Hernandez, C. [Electronics and Telecommunications Department, Scientific Research and Advanced Studies of Ensenada (CICESE), Km. 107 Carret. Tij-Ens., 22860 Ensenada, B.C. (Mexico)], E-mail: ccruz@cicese.mx

    2009-10-15

    In this paper, the robust synchronization problem for coupled chaotic Nd:YAG lasers is addressed. We resort to complex systems theory to achieve chaos synchronization. Based on stability theory, it is shown that the state trajectories of the perturbed error synchronization are ultimately bounded, provided the unperturbed synchronization error system is exponentially stable, and some conditions on the bounds of the perturbation terms are satisfied. So that, encoding, transmission, and decoding in chaotic optical communications are presented. We analyze the transmission and recovery of encrypted information when parameter mismatches are considered. Computer simulations are provided to show the effectiveness of this robustness synchronization property, we present the encrypted transmission of image messages, and we show that, the transmitted image is faithfully recovered.

  12. Cytopathology whole slide images and adaptive tutorials for postgraduate pathology trainees: a randomized crossover trial.

    Science.gov (United States)

    Van Es, Simone L; Kumar, Rakesh K; Pryor, Wendy M; Salisbury, Elizabeth L; Velan, Gary M

    2015-09-01

    To determine whether cytopathology whole slide images and virtual microscopy adaptive tutorials aid learning by postgraduate trainees, we designed a randomized crossover trial to evaluate the quantitative and qualitative impact of whole slide images and virtual microscopy adaptive tutorials compared with traditional glass slide and textbook methods of learning cytopathology. Forty-three anatomical pathology registrars were recruited from Australia, New Zealand, and Malaysia. Online assessments were used to determine efficacy, whereas user experience and perceptions of efficiency were evaluated using online Likert scales and open-ended questions. Outcomes of online assessments indicated that, with respect to performance, learning with whole slide images and virtual microscopy adaptive tutorials was equivalent to using traditional methods. High-impact learning, efficiency, and equity of learning from virtual microscopy adaptive tutorials were strong themes identified in open-ended responses. Participants raised concern about the lack of z-axis capability in the cytopathology whole slide images, suggesting that delivery of z-stacked whole slide images online may be important for future educational development. In this trial, learning cytopathology with whole slide images and virtual microscopy adaptive tutorials was found to be as effective as and perceived as more efficient than learning from glass slides and textbooks. The use of whole slide images and virtual microscopy adaptive tutorials has the potential to provide equitable access to effective learning from teaching material of consistently high quality. It also has broader implications for continuing professional development and maintenance of competence and quality assurance in specialist practice. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Online Job Tutorials @ the Public Library: Best Practices from Carnegie Library of Pittsburgh's Job & Career Education Center

    Directory of Open Access Journals (Sweden)

    Rhea M. Hebert

    2013-09-01

    Full Text Available This article describes the Job & Career Education Center (JCEC tutorial project completed in September of 2012. The article also addresses the website redesign implemented to highlight the tutorials and improve user engagement with JCEC online resources. Grant monies made it possible for a Digital Outreach Librarian to create a series of tutorials with the purpose of providing job-related assistance beyond the JCEC in the Carnegie Library of Pittsburgh—Main location. Benchmarking, planning, implementation, and assessment are addressed. A set of best practices for all libraries (public, academic, school, special are presented. Best practices are applicable to tutorials created with software other than Camtasia, the software used by the JCEC project.

  14. Challenge of Engaging All Students via Self-Paced Interactive Electronic Learning Tutorials for Introductory Physics

    Science.gov (United States)

    DeVore, Seth; Marshman, Emily; Singh, Chandralekha

    2017-01-01

    As research-based, self-paced electronic learning tools become increasingly available, a critical issue educators encounter is implementing strategies to ensure that all students engage with them as intended. Here, we first discuss the effectiveness of electronic learning tutorials as self-paced learning tools in large enrollment brick and mortar…

  15. Synchronization in a PLC/VAX-based control and data-acquisition system of a nuclear-fusion experiment

    International Nuclear Information System (INIS)

    Schmidt, V.; Flor, G.; Hemming, O.N.; Luchetta, A.; Manduchi, G.; Vitturi, S.

    1990-01-01

    This paper describes the concept and implementation details of the synchronization mechanisms used in the control and data-acquisition system of the RFX (Reversed-Field Experiment) nuclear-fusion experimental device, at present under construction in Padova, Italy, within the framework of the co-ordinated nuclear-fusion research programme of the European Communities. The system employs industrial PLCs for the 'slow' control and monitoring functions, and a VAX-based CAMAC for the 'fast' functions of trigger-signal generation and data acquisition during the experiment pulses. All subsystems communicate via Ethernet, using compatible software protocols. The operational sequence of the complete system is governed by a single state machine implemented on a PLC-based supervisor system. Equivalent 'slave' state machines are implemented on all other subsystems (PLC- and VAX-based). These state machines are synchronized by means of the exchange of messages via Ethernet. This paper deals in detail with the following components which are involved in system synchronization: The Message Exchange System which implements the system-wide exchange of short messages; the Scheduler programs which implement the state machine on the various computing nodes, and which make use of the Message Exchange System. (orig.)

  16. A tutorial on queuing and trunking with applications to communications

    CERN Document Server

    Tranter, William H

    2012-01-01

    The motivation for developing this synthesis lecture was to provide a tutorial on queuing and trunking, with extensions to networks of queues, suitable for supplementing courses in communications, stochastic processes, and networking. An essential component of this lecture is MATLAB-based demonstrations and exercises, which can be easily modified to enable the student to observe and evaluate the impact of changing parameters, arrival and departure statistics, queuing disciplines, the number of servers, and other important aspects of the underlying system model. Much of the work in this lecture

  17. Approximating Literacy Practices in Tutorials: What Is Learned and What Matters for Teacher Preparation

    Science.gov (United States)

    Hoffman, James V.; Wetzel, Melissa Mosley; Peterson, Katie

    2016-01-01

    In this study, we examined the learning of preservice teachers associated with the features of a literacy tutorial experience. Our qualitative study focused on the close inspection of the experiences of 7 focus cases out of the 19 preservice teachers enrolled in our program across a one-semester tutorial experience. Through our research we…

  18. Synchronization of hyperchaotic oscillators via single unidirectional chaotic-coupling

    International Nuclear Information System (INIS)

    Zou Yanli; Zhu Jie; Chen Guanrong; Luo Xiaoshu

    2005-01-01

    In this paper, synchronization of two hyperchaotic oscillators via a single variable's unidirectional coupling is studied. First, the synchronizability of the coupled hyperchaotic oscillators is proved mathematically. Then, the convergence speed of this synchronization scheme is analyzed. In order to speed up the response with a relatively large coupling strength, two kinds of chaotic coupling synchronization schemes are proposed. In terms of numerical simulations and the numerical calculation of the largest conditional Lyapunov exponent, it is shown that in a given range of coupling strengths, chaotic-coupling synchronization is quicker than the typical continuous-coupling synchronization. Furthermore, A circuit realization based on the chaotic synchronization scheme is designed and Pspice circuit simulation validates the simulated hyperchaos synchronization mechanism

  19. Synchronization of two chaotic systems: Dynamic compensator approach

    International Nuclear Information System (INIS)

    Chen, C.-K.; Lai, T.-W.; Yan, J.-J.; Liao, T.-L.

    2009-01-01

    This study is concerned with the identical synchronization problem for a class of chaotic systems. A dynamic compensator is proposed to achieve the synchronization between master and slave chaotic systems using only the accessible output variables. A sufficient condition is also proposed to ensure the global synchronization. Furthermore, the strictly positive real (SPR) restriction, which is normally required in most of the observer-based synchronization schemes, is released in our approach. Two numerical examples are included to illustrate the proposed scheme.

  20. Usability of synchronization for cognitive modeling

    International Nuclear Information System (INIS)

    Diebner, Hans H.; Grond, Florian

    2005-01-01

    We discuss the synchronization features of a previously introduced adaptive system for dynamics recognition in more detail. We investigate the usability of synchronization for modeling and parameter estimations. It is pointed out inhowfar the adaptive system based on synchronization can become a powerful tool in modeling. The adaptive system can store modules of pre-adapted dynamics and is potentially capable of undergoing self-modification. We compare the stored modules with pre-knowledge that a modeler puts into his or her models. In this sense the adaptive system functions like an expert system

  1. Position paper: Web tutorials and Information Literacy research

    DEFF Research Database (Denmark)

    Hyldegård, Jette

    2011-01-01

    Position paper on future research challenges regarding web tutorials with the aim of supporting and facilitating Information Literacy in an academic context. Presented and discussed at the workshop: Social media & Information Practices, track on Information literacy practices, University of Borås...

  2. University tutorials in the setting of the European Higher Education Area: current profiles

    Directory of Open Access Journals (Sweden)

    Carolina FERNÁNDEZ-SALINERO MIGUEL

    2014-07-01

    Full Text Available In the new setting promoted by the European Higher Education Area, university guidance and tutorials have become more important than ever. We understand tutorials as part of the teaching responsibility in which a more personal interaction between professor and student, professor and novice teacher, or student and student is established, and whose goal is to guide learning according to the individual characteristics and learning styles of the individuals involved. Now is the time to set up guidance and tutorials systems for students –both during the training process and in their first professional steps– and for novice teachers also. Among such systems we can mention professor coaching, peer mentoring, professional tutoring in training centres or mentoring of an experienced university professor on the novice teacher.

  3. Space-based pseudo-fixed latitude observation mode based on the characteristics of geosynchronous orbit belt

    Science.gov (United States)

    Hu, Yun-peng; Chen, Lei; Huang, Jian-yu

    2017-08-01

    The US Lincoln Laboratory proved that space-based visible (SBV) observation is efficient to observe space objects, especially Geosynchronous Orbit (GEO) objects. After that, SBV observation plays an important role in the space surveillance. In this paper, a novel space-based observation mode is designed to observe all the GEO objects in a relatively short time. A low earth orbit (LEO) satellite, especially a dawn-dusk sun-synchronous orbit satellite, is useful for space-based observation. Thus, the observation mode for GEO objects is based on a dawn-dusk sun-synchronous orbit satellite. It is found that the Pinch Point (PP) regions proposed by the US Lincoln Laboratory are spreading based on the analysis of the evolution principles of GEO objects. As the PP regions becoming more and more widely in the future, many strategies based on it may not be efficient any more. Hence, the key point of the space-based observation strategy design for GEO objects should be emphasized on the whole GEO belt as far as possible. The pseudo-fixed latitude observation mode is proposed in this paper based on the characteristics of GEO belt. Unlike classical space-based observation modes, pseudo-fixed latitude observation mode makes use of the one-dimensional attitude adjustment of the observation satellite. The pseudo-fixed latitude observation mode is more reliable and simple in engineering, compared with the gazing observation mode which needs to adjust the attitude from the two dimensions. It includes two types of attitude adjustment, i.e. daily and continuous attitude adjustment. Therefore, the pseudo-fixed latitude observation mode has two characteristics. In a day, the latitude of the observation region is fixed and the scanning region is about a rectangle, while the latitude of the observation region centre changes each day in a long term based on a daily strategy. The capabilities of a pseudo-fixed latitude observation instrument with a 98° dawn-dusk sun-synchronous orbit are

  4. A Tutorial on the Cross-Entropy Method

    NARCIS (Netherlands)

    de Boer, Pieter-Tjerk; Kroese, Dirk; Mannor, Shie; Rubinstein, Reuven Y.

    The cross-entropy (CE) method is a new generic approach to combinatorial and multi-extremal optimization and rare event simulation. The purpose of this tutorial is to give a gentle introduction to the CE method. We present the CE methodology, the basic algorithm and its modi��?cations, and

  5. Chaos synchronization of the energy resource system

    International Nuclear Information System (INIS)

    Li Xiuchun; Xu Wei; Li Ruihong

    2009-01-01

    This paper presents the chaos synchronization problem for new dynamical system (that is, energy resource demand-supply system), where the controller is designed using two different control methods. Firstly, based on stability criterion of linear system, chaotic synchronization is achieved with the help of the active theory, and accordingly, the simulation results are given for verifying the feasibility of the method. Secondly, based on Lyapunov stability theory, on the assumption that all the parameters of the system are unknown, adaptive control approach is proposed to make the states of two chaotic systems asymptotic synchronization. In the end, numerical simulations are used to show the effectiveness of the proposed control method.

  6. OAI-PMH for resource harvesting, tutorial 2

    CERN Multimedia

    CERN. Geneva; Nelson, Michael

    2005-01-01

    A variety of examples have arisen in which the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) has been used for applications beyond bibliographic metadata interchange. One of these examples is the use of OAI-PMH to harvest resources and not just metadata. Advanced resource discovery and preservations capabilities are possible by combining complex object formats such as MPEG-21 DIDL, METS and SCORM with the OAI-PMH. In this tutorial, we review community conventions and practices that have provided the impetus for resource harvesting. We show how the introduction of complex object formats for the representation of resources leads to a robust, OAI-PMH-based framework for resource harvesting. We detail how complex object formats fit in the OAI-PMH data model, and how (compound) digital objects can be represented using a complex object format for exposure by an OAI-PMH repository. We also cover tools that are available for the implementation of an OAI-PMH-based resource harvesting solution. Fu...

  7. Synchronization of modified Colpitts oscillators with structural perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Kammogne, Soup Tewa; Fotsin, H B, E-mail: hbfotsin@yahoo.fr [Laboratoire d' electronique, Departement de Physique, Faculte des sciences, Universite de Dschang, PO Box 067, Dschang (Cameroon)

    2011-06-01

    This paper deals with the problem of the synchronization of uncertain modified Colpitts oscillators. Considering the effect of external disturbances on the system parameters and nonlinear control inputs, a robust controller based on Lyapunov theory is designed for the output synchronization between a slave system and a master system in order to ensure the synchronization of uncertain modified Colpitts oscillator systems. This approach was chosen not only to guarantee a stable synchronization but also to reduce the effect of external perturbation. Nonadaptive feedback synchronization with only one controller for the system is investigated. Numerical simulations are performed to confirm the efficiency of the proposed control scheme.

  8. Robust chaos synchronization based on adaptive fuzzy delayed ...

    Indian Academy of Sciences (India)

    cations in secure communication, economics, signal generator design, chemical reaction, ... that may cause instability and poor performance. ... synchronization error system is asymptotically stable with a guaranteed H∞ norm bound.

  9. Tracking target objects orbiting earth using satellite-based telescopes

    Science.gov (United States)

    De Vries, Willem H; Olivier, Scot S; Pertica, Alexander J

    2014-10-14

    A system for tracking objects that are in earth orbit via a constellation or network of satellites having imaging devices is provided. An object tracking system includes a ground controller and, for each satellite in the constellation, an onboard controller. The ground controller receives ephemeris information for a target object and directs that ephemeris information be transmitted to the satellites. Each onboard controller receives ephemeris information for a target object, collects images of the target object based on the expected location of the target object at an expected time, identifies actual locations of the target object from the collected images, and identifies a next expected location at a next expected time based on the identified actual locations of the target object. The onboard controller processes the collected image to identify the actual location of the target object and transmits the actual location information to the ground controller.

  10. Instructional and regulative discourse in language tutorials: An ...

    African Journals Online (AJOL)

    The research is situated in the context of literature tutorials. To achieve this goal Bernstein's (1990; 1996) pedagogic discourse is employed, as it was used by Buzzelli and Johnston (2001). Keywords: language learning, learning process, teacher-student interaction, participation, potentially offensive views, pedagogic ...

  11. Scheduling algorithm for data relay satellite optical communication based on artificial intelligent optimization

    Science.gov (United States)

    Zhao, Wei-hu; Zhao, Jing; Zhao, Shang-hong; Li, Yong-jun; Wang, Xiang; Dong, Yi; Dong, Chen

    2013-08-01

    Optical satellite communication with the advantages of broadband, large capacity and low power consuming broke the bottleneck of the traditional microwave satellite communication. The formation of the Space-based Information System with the technology of high performance optical inter-satellite communication and the realization of global seamless coverage and mobile terminal accessing are the necessary trend of the development of optical satellite communication. Considering the resources, missions and restraints of Data Relay Satellite Optical Communication System, a model of optical communication resources scheduling is established and a scheduling algorithm based on artificial intelligent optimization is put forwarded. According to the multi-relay-satellite, multi-user-satellite, multi-optical-antenna and multi-mission with several priority weights, the resources are scheduled reasonable by the operation: "Ascertain Current Mission Scheduling Time" and "Refresh Latter Mission Time-Window". The priority weight is considered as the parameter of the fitness function and the scheduling project is optimized by the Genetic Algorithm. The simulation scenarios including 3 relay satellites with 6 optical antennas, 12 user satellites and 30 missions, the simulation result reveals that the algorithm obtain satisfactory results in both efficiency and performance and resources scheduling model and the optimization algorithm are suitable in multi-relay-satellite, multi-user-satellite, and multi-optical-antenna recourses scheduling problem.

  12. On synchronized regions of discrete-time complex dynamical networks

    International Nuclear Information System (INIS)

    Duan Zhisheng; Chen Guanrong

    2011-01-01

    In this paper, the local synchronization of discrete-time complex networks is studied. First, it is shown that for any natural number n, there exists a discrete-time network which has at least left floor n/2 right floor +1 disconnected synchronized regions for local synchronization, which implies the possibility of intermittent synchronization behaviors. Different from the continuous-time networks, the existence of an unbounded synchronized region is impossible for discrete-time networks. The convexity of the synchronized regions is also characterized based on the stability of a class of matrix pencils, which is useful for enlarging the stability region so as to improve the network synchronizability.

  13. Learners' Use of Communication Strategies in Text-Based and Video-Based Synchronous Computer-Mediated Communication Environments: Opportunities for Language Learning

    Science.gov (United States)

    Hung, Yu-Wan; Higgins, Steve

    2016-01-01

    This study investigates the different learning opportunities enabled by text-based and video-based synchronous computer-mediated communication (SCMC) from an interactionist perspective. Six Chinese-speaking learners of English and six English-speaking learners of Chinese were paired up as tandem (reciprocal) learning dyads. Each dyad participated…

  14. Professionalizing tutors and tutorials in higher education

    Directory of Open Access Journals (Sweden)

    Colunga, Silvia

    2012-01-01

    Full Text Available The paper analyzes the necessity of professionalizing training of university teachers performing tutorial activities in higher education as a response to the demands of pupils following a part-time model. Permanent training of tutor is emphasized as a way to enhance professional and personal accomplishments. This training gives priority to educative orientation and interventional actions.

  15. Online synchronous communication in the second-language classroom

    Directory of Open Access Journals (Sweden)

    Elizabeth Murphy

    2010-07-01

    Full Text Available Abstract: The study reported on in this paper used a framework of benefits, challenges and solutions to categorize data from a design experiment using synchronous online communication for learning French as a second language (FSL. Participants were 92 Grade 6, FSL students and four teachers from urban and rural areas of Newfoundland, Canada. Data collection relied on online observation, teachers’ use of blogs and an online discussion forum, face-to-face planning and reflection meetings for teachers as well as interviews with all participants. Benefits included independence and peer-learning; authenticity and motivation; anonymity and confidence; enhanced self-esteem. Challenges related to teacher multi-tasking; poor sound quality; technical problems; momentum; grouping; scheduling. Solutions included use of student moderators; audio tutorials and direct messaging; activity tutorials; technical support and capacity building. The categories and their subcategories were grouped into two themes of positive affect and student-centered learning. Résumé : L’étude décrite dans le présent article a utilisé un cadre prenant en considération les bénéfices, les défis et les solutions afin de classer les données d’un dispositif expérimental utilisant la communication synchrone en ligne pour l’apprentissage du français langue seconde (FLS. Les participants étaient 92 élèves en FLS de sixième année et quatre enseignants de milieux urbains et ruraux de Terre-Neuve, Canada. La collecte des données s’est fondée sur l’observation en ligne, l’utilisation de cybercarnets et d’un forum de discussion en ligne par les enseignants, la planification en face-à-face et des réunions de réflexion pour les enseignants, ainsi que des entrevues avec tous les participants. Les bénéfices comprenaient : l’indépendance et l’apprentissage entre pairs; l’authenticité et la motivation; l’anonymat et la confiance; l

  16. The synchronization of three fractional differential systems

    International Nuclear Information System (INIS)

    Li Changpin; Yan Jianping

    2007-01-01

    In this paper, a new method is proposed and applied to the synchronization of fractional differential systems (or 'differential systems with fractional orders'), where both drive and response systems have the same dimensionality and are coupled by the driving signal. The present technique is based on the stability criterion of linear fractional systems. This method is implemented in (chaos) synchronization of the fractional Lorenz system, Chen system and Chua circuit. Numerical simulations show the present synchronization method works well

  17. Synchronizing a class of uncertain chaotic systems

    International Nuclear Information System (INIS)

    Chen Maoyin; Zhou Donghua; Shang Yun

    2005-01-01

    This Letter deals with the synchronization of a class of uncertain chaotic systems in the drive-response framework. A robust adaptive observer based response system is designed to synchronize a given chaotic system with unknown parameters and external disturbances. Lyapunov stability ensures the global synchronization between the drive and response systems even if Lipschitz constants on function matrices and bounds on uncertainties are unknown. Numerical simulation of Genesio-Tesi system verifies the effectiveness of this scheme

  18. Mixed synchronization in chaotic oscillators using scalar coupling

    Energy Technology Data Exchange (ETDEWEB)

    Bhowmick, Sourav K.; Hens, Chittaranjan [CSIR – Indian Institute of Chemical Biology, Jadavpur, Kolkata 700032 (India); Ghosh, Dibakar, E-mail: drghosh_math@yahoo.co.in [Department of Mathematics, University of Kalyani, West Bengal 741235 (India); Dana, Syamal K. [CSIR – Indian Institute of Chemical Biology, Jadavpur, Kolkata 700032 (India)

    2012-07-23

    We report experimental evidence of mixed synchronization in two unidirectionally coupled chaotic oscillators using a scalar coupling. In this synchronization regime, some of the state variables may be in complete synchronization while others may be in anti-synchronization state. We extended the theory by using an adaptive controller with an updating law based on Lyapunov function stability to include parameter fluctuation. Using the scheme, we implemented a cryptographic encoding for digital signal through parameter modulation. -- Highlights: ► We provided experimental evidence of the mixed synchronization scheme while other methods are mostly theoretical nature. ► We numerically studied adaptive mixed synchronization when the parameters are not completely known using scalar coupling. ► We proposed a secure communication system where three digital messages are transmitted using parameter modulation.

  19. Detection of generalized synchronization using echo state networks

    Science.gov (United States)

    Ibáñez-Soria, D.; Garcia-Ojalvo, J.; Soria-Frisch, A.; Ruffini, G.

    2018-03-01

    Generalized synchronization between coupled dynamical systems is a phenomenon of relevance in applications that range from secure communications to physiological modelling. Here, we test the capabilities of reservoir computing and, in particular, echo state networks for the detection of generalized synchronization. A nonlinear dynamical system consisting of two coupled Rössler chaotic attractors is used to generate temporal series consisting of time-locked generalized synchronized sequences interleaved with unsynchronized ones. Correctly tuned, echo state networks are able to efficiently discriminate between unsynchronized and synchronized sequences even in the presence of relatively high levels of noise. Compared to other state-of-the-art techniques of synchronization detection, the online capabilities of the proposed Echo State Network based methodology make it a promising choice for real-time applications aiming to monitor dynamical synchronization changes in continuous signals.

  20. Robust anti-synchronization of uncertain chaotic systems based on multiple-kernel least squares support vector machine modeling

    International Nuclear Information System (INIS)

    Chen Qiang; Ren Xuemei; Na Jing

    2011-01-01

    Highlights: Model uncertainty of the system is approximated by multiple-kernel LSSVM. Approximation errors and disturbances are compensated in the controller design. Asymptotical anti-synchronization is achieved with model uncertainty and disturbances. Abstract: In this paper, we propose a robust anti-synchronization scheme based on multiple-kernel least squares support vector machine (MK-LSSVM) modeling for two uncertain chaotic systems. The multiple-kernel regression, which is a linear combination of basic kernels, is designed to approximate system uncertainties by constructing a multiple-kernel Lagrangian function and computing the corresponding regression parameters. Then, a robust feedback control based on MK-LSSVM modeling is presented and an improved update law is employed to estimate the unknown bound of the approximation error. The proposed control scheme can guarantee the asymptotic convergence of the anti-synchronization errors in the presence of system uncertainties and external disturbances. Numerical examples are provided to show the effectiveness of the proposed method.