1,721,111 research outputs found
Bau(m) Berlin: Making the Future Commons, Making Connections, Making Things
No full textThis project takes place in Friedrichshain, Berlin, Germany and presents the design of a Public Condenser along the Straße der Pariser Kommune named ’Bau(m) Berlin’. The project is part of the Public Building Graduation Studio and looks into the topic of designing a ’new urban lounge and commons’ through the process of Research by Design. Through field research and urban analysis, three issues came to the forth in the Friedrichshain area; A disconnection between residents, a missing framework for social (re-)integration and low quality green space. These issues consequently led to choosing the project site along the Straße der Pariser Kommune and forming the following research question:”What if there could be an architecture that pushes interaction so that the social gap between people could be bridged whilst functioning as a platform that helps people to (re-) enter society?”In order to tackle the pre-described issues, the project takes the notion of ’building’ and dissects it into ’Building the Future Commons’, ’Building Connections’ and ’Building Things’. Together they describe and result into the project Bau(m). The ’m’ in Bau(m) entails the notion and concept of Multiplicity, e.i. the idea that a thing, in this case a public building, can be used in multiple ways, for various programmatic functions, throughout time. For me, this meant seeing architecture as a framework that allows for adaptable use of a building. Consequently, the building is designed as a pavilion within the park stretching along the Straße der Pariser Kommune and has one big roof supported by a grid structure column repetition made from timber. The columns are bended so that together, they form an arch-shaped pattern. By seeing the building as part of the park, the park is equally redesigned into a park of higher quality with an urban route that stretches through the building and connects the Ostbahnhof train station with the Karl-Marx-Allee further North.The main function of the building is a workshop space for various crafts, amongst which furniture making, as it uses the method of making as a way of bringing people together and getting those in need back on into society. This workshop space stretches into the basement and thus forms the substructure of an urban square that exists in front of the building.Public Building: Urban CommonsArchitecture, Urbanism and Building Sciences | Public Buildin
Piezoelectric Energy Harvesting from Low-Frequency Vibrations Based on Magnetic Plucking and Indirect Impacts
Full text linkThis work proposes a mono-axial piezoelectric energy harvester based on the innovative combination of magnetic plucking and indirect impacts, e.g., impacts happening on the package of the harvester. The harvester exploits a permanent magnet placed on a non-magnetic mass, free to move within a predefined bounded region located in front of a piezoelectric bimorph cantilever equipped with a magnet as the tip mass. When the harvester is subjected to a low-frequency external acceleration, the moving mass induces an abrupt deflection and release of the cantilever by means of magnetic coupling, followed by impacts of the same mass against the harvester package. The combined effect of magnetic plucking and indirect impacts induces a frequency up-conversion. A prototype has been designed, fabricated, fastened to the wrist of a person by means of a wristband, and experimentally tested for different motion levels. By setting the magnets in a repulsive configuration, after 50 s of consecutive impacts induced by shaking, an energy of 253.41 μJ has been stored: this value is seven times higher compared to the case of harvester subjected to indirect impacts only, i.e., without magnetic coupling. This confirms that the combination of magnetic plucking and indirect impacts triggers the effective scavenging of electrical energy even from low-frequency non-periodical mechanical movements, such as human motion, while preserving the reliability of piezoelectric components
Magnetless electromagnetic contactless interrogation technique for unwired conductive resonators
No full textAn electromagnetic contactless interrogation technique to induce and sense mechanical vibrations on miniaturised electrically conductive resonant structures is presented. The structures can be used as passive resonant sensors with proximate contactless readout. No use is made of poling magnets or wired connections to the resonator that is not required to have magnetic properties. An external coil arrangement has one driving and two pickup coils. The driving coil generates a DC magnetic field and two AC magnetic fields at different frequencies: one for excitation and one for probing. Both the AC magnetic fields induce eddy currents on the conductive surface of the resonating structure. The eddy currents at the frequency of the excitation field interact with the DC magnetic field causing alternating forces, which can set the resonating structure into vibration. The eddy currents at the frequency of the probing field generate a magnetic field that is modulated by the vibrations and detected by the pickup coils. A mathematical model of the interrogation principle has been derived and confirmed by numerical solutions. The experimental demonstration is provided by results obtained on an aluminium cantilever resonator
Quartz Crystal Resonator Sensor with Printed-on-Crystal Coil for Dual-Harmonic Electromagnetic Contactless Interrogation
No full textA novel quartz crystal resonator (QCR) sensor with a printed-on-crystal conductive coil, named sensor coil, is presented. The sensor coil electromagnetically coupled to an external readout coil allow to perform contactless interrogation of the QCR working as a stand-alone sensor unit. A frequency-domain readout technique is adopted that allows dual-harmonic operation by detecting the QCR frequencies of the fundamental and third harmonic, and offers first-order independence from the stand-off distance between the sensor and the readout unit. The QCR electrodes and sensor coil have been printed on a 330-μm-thick bare AT-cut quartz crystal exploiting the aerosol jet printing technology. The fabricated QCR sensor has reference values of the fundamental and third harmonic frequencies at 4.77 and 14.22 MHz, respectively. Distance-independent contactless operation has been demonstrated for distances up to 12 mm. The readout frequencies deviate from reference values less than 10 and 90 ppm for the fundamental and third harmonic, respectively, thus validating the proposed principle
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Piezoelectric Multi-Frequency Nonlinear MEMS Converter for Energy Harvesting from Broadband Vibrations
No full textThis paper proposes a MEMS piezoelectric converter for energy harvesting from vibrations which exploits nonlinear effects to broaden the operating bandwidth. The converter is composed of an array of cantilevers with different geometric dimensions. Piezoelectric layer and electrodes have been deposited on the cantilevers by a custom low-curing temperature post process. Nonlinearity is achieved by the magnetic interaction of a magnet and ferromagnetic particles deposited on the cantilever tips. Preliminary results show that the converter behaves like a nonlinear system and a downshift of the resonant frequency of the cantilevers with respect to the linear resonant frequency is observed, as expected
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
