22,734 research outputs found

    Antenna Design and Implementation for the Future Space Ultra-Long Wavelength Radio Telescope

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    In radio astronomy, the Ultra-Long Wavelengths (ULW) regime of longer than 10 m (frequencies below 30 MHz), remains the last virtually unexplored window of the celestial electromagnetic spectrum. The strength of the science case for extending radio astronomy into the ULW window is growing. However, the opaqueness of the Earth's ionosphere makes ULW observations by ground-based facilities practically impossible. Furthermore, the ULW spectrum is full of anthropogenic radio frequency interference (RFI). The only radical solution for both problems is in placing an ULW astronomy facility in space. We present a concept of a key element of a space-borne ULW array facility, an antenna that addresses radio astronomical specifications. A tripole-type antenna and amplifier are analysed as a solution for ULW implementation. A receiver system with a low power dissipation is discussed as well. The active antenna is optimized to operate at the noise level defined by the celestial emission in the frequency band 1 - 30 MHz. Field experiments with a prototype tripole antenna enabled estimates of the system noise temperature. They indicated that the proposed concept meets the requirements of a space-borne ULW array facility.Comment: Submitted to Experimental Astronomy, 23 pages, 17 figure

    Automation of the space station core module power management and distribution system

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    Under the Advanced Development Program for Space Station, Marshall Space Flight Center has been developing advanced automation applications for the Power Management and Distribution (PMAD) system inside the Space Station modules for the past three years. The Space Station Module Power Management and Distribution System (SSM/PMAD) test bed features three artificial intelligence (AI) systems coupled with conventional automation software functioning in an autonomous or closed-loop fashion. The AI systems in the test bed include a baseline scheduler/dynamic rescheduler (LES), a load shedding management system (LPLMS), and a fault recovery and management expert system (FRAMES). This test bed will be part of the NASA Systems Autonomy Demonstration for 1990 featuring cooperating expert systems in various Space Station subsystem test beds. It is concluded that advanced automation technology involving AI approaches is sufficiently mature to begin applying the technology to current and planned spacecraft applications including the Space Station

    Distance Aware Relaying Energy-efficient: DARE to Monitor Patients in Multi-hop Body Area Sensor Networks

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    In recent years, interests in the applications of Wireless Body Area Sensor Network (WBASN) is noticeably developed. WBASN is playing a significant role to get the real time and precise data with reduced level of energy consumption. It comprises of tiny, lightweight and energy restricted sensors, placed in/on the human body, to monitor any ambiguity in body organs and measure various biomedical parameters. In this study, a protocol named Distance Aware Relaying Energy-efficient (DARE) to monitor patients in multi-hop Body Area Sensor Networks (BASNs) is proposed. The protocol operates by investigating the ward of a hospital comprising of eight patients, under different topologies by positioning the sink at different locations or making it static or mobile. Seven sensors are attached to each patient, measuring different parameters of Electrocardiogram (ECG), pulse rate, heart rate, temperature level, glucose level, toxins level and motion. To reduce the energy consumption, these sensors communicate with the sink via an on-body relay, affixed on the chest of each patient. The body relay possesses higher energy resources as compared to the body sensors as, they perform aggregation and relaying of data to the sink node. A comparison is also conducted conducted with another protocol of BAN named, Mobility-supporting Adaptive Threshold-based Thermal-aware Energy-efficient Multi-hop ProTocol (M-ATTEMPT). The simulation results show that, the proposed protocol achieves increased network lifetime and efficiently reduces the energy consumption, in relative to M-ATTEMPT protocol.Comment: IEEE 8th International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA'13), Compiegne, Franc

    MatriksMovie: Building The Nation Character Through Movie-Based Realistic Mathematics Education

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    The root of RME is Hans Freudenthal’s interpretations, mathematics as human activity and mathematics must be connected to reality. This study developed a mathematics teaching and learning model that includes the characteristics of RME packaged in production and utilization of educational films in the learning process, it is called MATRiKSMovie Activity. Activity theory is based on Vygotsky's cultural-historical psychology and it focuses on understanding human activity and work practices. Practice of problem solving in real life can lead students to reflect, and build nation character. This research question are how to develop and implement a valid, practical and effective model of teaching and learning with movie based RME approach in Senior High Schools and its effect on students character and learning outcomes. Conclusion of this research are model of teaching and learning with movie based RME approach met the criteria of the content and construct validity, practicality, and effectiveness as it resulted in some positive impacts on the pupils at Grade 10 in Senior High Schools, mathematics learning with movie-based RME approach can serve to build student character as well as the civilization of the nation's dignity in order to educate the nation life, activities and process skills of students in mathematics learning with movie based RME approach has provided a positive impacts on the student learning outcomes (cognitive, affective, and psychomotor). Model of teaching and learning with Movie-based RME approach can be applied in learning mathematics and should be developed further by taking into account students' environment, conditions and facilities available. Humanistic mathematics learning should be developed to build the nation character. Keywords: MATRiKSMovie, Realistic Mathematics Education, Movie, the Nation Characte

    BitBox!:A case study interface for teaching real-time adaptive music composition for video games

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    Real-time adaptive music is now well-established as a popular medium, largely through its use in video game soundtracks. Commercial packages, such as fmod, make freely available the underlying technical methods for use in educational contexts, making adaptive music technologies accessible to students. Writing adaptive music, however, presents a significant learning challenge, not least because it requires a different mode of thought, and tutor and learner may have few mutual points of connection in discovering and understanding the musical drivers, relationships and structures in these works. This article discusses the creation of ‘BitBox!’, a gestural music interface designed to deconstruct and explain the component elements of adaptive composition through interactive play. The interface was displayed at the Dare Protoplay games exposition in Dundee in August 2014. The initial proof-of- concept study proved successful, suggesting possible refinements in design and a broader range of applications

    D-touch: A Consumer-Grade Tangible Interface Module and Musical Applications

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    We define a class of tangible media applications that can be implemented on consumer-grade personal computers. These applications interpret user manipulation of physical objects in a restricted space and produce unlocalized outputs. We propose a generic approach to the implementation of such interfaces using flexible fiducial markers, which identify objects to a robust and fast video-processing algorithm, so they can be recognized and tracked in real time. We describe an implementation of the technology, then report two new, flexible music performance applications that demonstrate and validate it
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