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31.
The embedded-object concept, EOC, applies common object-oriented software methods to Lego-like hardware-software entities. These modular entities, representing objects in object-oriented design, function as electronic building blocks that can be assembled into new embedded systems. The goal of the EOC is to make embedded-system design faster and easier while preserving the commercial applicability of the resulting devices. 相似文献
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33.
Due to rising fuel costs, the substantial price for CO2 emissions and decreasing wind power costs, wind power might become the least expensive source of power for an increasing number of power systems. This poses the questions of how wind power might change optimal investments in other forms of power production and what kind of means could be used to increase power system flexibility in order to incorporate the variable power production from wind power in a cost-effective manner. 相似文献
34.
Thin film bulk acoustic wave filter 总被引:1,自引:0,他引:1
Ylilammi M Ellä J Partanen M Kaitila J 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2002,49(4):535-539
Thin film bulk acoustic wave (BAW) resonators (FBAR) are fabricated on a silicon nitride bridge using a ZnO piezolayer on a glass substrate and surface micromachining by standard thin film technology. These resonators exhibit a coupling constant k/sub t//sup 2/=7.8% at the first thickness extensional wave mode and are used as impedance elements in a ladder filter in the 1-GHz frequency band of mobile telecommunications. An electrical equivalent circuit is used to characterize the properties of the resonators and to show how the performance of the filter depends on the parameters of the resonators. 2.5% bandwidth, 2.8-dB insertion loss, and 35-dB selectivity are obtained in a filter with six resonators. The technology can be used to manufacture miniature microwave filters without any additional inductances. 相似文献
35.
We present an easy interaction technique for accessing location-based contextual data shown on a head-worn wearable computer
display. Our technique, called Context Compass, is based on a regular compass metaphor. Each object belonging to the user’s
current context is visualised on a linear compass shown on the screen. The object directly in front of the user is shown in
the middle of the compass and can be activated. Whenever the user turns his or her head, the objects on the screen move accordingly.
Therefore, an object can be selected by simply turning one’s head towards it. Context Compass consumes a minimal amount of
screen space, making it ideal for usage with see-through head-worn displays. An initial pilot study, applying a newly developed
usability method customised especially for Context Compass, revealed that Context Compass can be learned virtually immediately.
Further, the method itself proved to be successful in evaluating techniques such as Context Compass. 相似文献
36.
In many user interfaces with restricted input capabilities, a time-out is used to automatically change the user interface (UI) from one mode to another. In this paper, we study the learning of time-outs and the effect of feedback on it in the case of mobile phone text entry. The effects of three different feedback schemes (auditory/visual/no feedback) on the learning of two different time-out lengths were compared. We measured the response time (RT) from the time-out occurrence to the time of the users action. Error rates and the development of the RTs in different schemes were used as measures of learning. We also studied if the users learned to estimate the time-out lengths, or if they just reacted to the available feedback. There were three main findings. Without feedback, RTs had a great variation. Auditory feedback enabled faster RTs than visual feedback. Finally, we found evidence of short-term learning, but not much of a lasting effect. The possible application of adapting time-out length to user RT is discussed. 相似文献
37.
Giulio?IacucciEmail author Juha?Kela Pekka?Pehkonen 《Personal and Ubiquitous Computing》2004,8(2):100-109
Information technology research has mainly focussed on supporting visitors with guides, whilst a lot of opportunities for the development of technology for collecting, manipulating and re-travelling through material from the visits remain unexplored. On the basis of observations from a specific setting, we have developed prototype technology to combine multimedia content with position information. In particular, we developed mobile support to record and organise multimedia using the walked path in order to preserve more of the experience of the visit. We created tools to edit and store multimedia paths. Additional components make it possible to configure a mixed-media environment to navigate a multimedia path, using such physical interfaces as gesturing, and link the recorded media to other artefacts. When discussing field observations of current practices and prototype trials, we investigate what kind of functionality is needed to support the whole activity of collecting, manipulating and playing multimedia content in combination with position information. 相似文献
38.
Juha Sinkkonen 《Solid-state electronics》1983,26(11):1111-1116
Interface resistance is studied by using the Landauer formula which relates the resistance to the quantum mechanical transmission coefficient. A simple rederivation of the Landauer formula is given. Using a step-like potential barrier as a model for the metal-semiconductor contact an analytical expression for the effective Richardson constant is derived. As an other application the grain boundary resistance in polycrystalline semiconductors is studied. The short-range potential fluctuation associated with the grain boundary is described by a rectangular potential barrier. The results for the grain boundary limited mobility cover both the strong and weak scattering regimes. 相似文献
39.
Yrjö Viisanen Juha Hatakka Seppo Ahonen Markku Kulmala 《Aerosol science and technology》2013,47(1):224-229
By means of a simple optical apparatus the levels and variations of concentrations of elemental carbon in particles were measured. Additionally, relations between variations of elemental carbon, lead, sulfate, total suspended particle, and nitrate concentrations were studied. Calibration was performed on real samples analyzed by a wet chemical method. 相似文献
40.
L. Juha M. F rní kov V. Hamplov J. Kodymov A. Mü llerov J. Kr sa L. L ska O. palek P. Kub t L. Stibor E. Koudoumas S. Couris 《Fullerenes, Nanotubes and Carbon Nanostructures》2000,8(4):289-318
Experiments designed to clarify the role of molecular oxygen in the photolysis of fullerene are described. The formation of oxygen-fullerene adducts, both in fullerene solutions in various solvents and in micro-crystallites formed by evaporating these solutions, and their photolysis was studied under various experimental conditions. The results confirm that the role of oxygen in the photolysis process in these systems is ambivalent and highly dependent on the conditions under which the irradiation of the fullerenes occurs (wavelength and intensity of the photolyzing radiation, character of the solvent molecules, presence of additional molecules in the solvent-fullerene-oxygen system, etc.). 相似文献