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排序方式: 共有648条查询结果,搜索用时 31 毫秒
61.
Die Dynamik der Technikentwicklung in den vergangenen Jahren konfrontiert Datenschützer immer wieder aufs Neue mit Risiken für die Privatsph?re der Betroffenen — und es sieht so aus, als ob sich dies in den n?chsten Jahren und Jahrzehnten nicht ?ndern wird. Konzepte für einen lebenslangen Datenschutz erfordern ein Umdenken vom kurzatmigen Systementwurf zu langfristigen und zukunftsf?higen Planungen. 相似文献
62.
Christian C. Hindrichsen Ninia S. Almind Simon H. Brodersen Rasmus Lou-Møller Karsten Hansen Erik V. Thomsen 《Journal of Electroceramics》2010,25(2-4):108-115
Piezoelectric thick films have increasing interest due to the potential high sensitivity and actuation force for MEMS sensors and actuators. The screen printing technique is a promising deposition technique for realizing piezoelectric thick films in the thickness range from 10–100 μm. In this work integration of a screen printed piezoelectric PZT thick film with silicon MEMS technology is shown. A high bandwidth triaxial accelerometer has been designed, fabricated and characterized. The voltage sensitivity is 0.31 mV/g in the vertical direction, 0.062 mV/g in the horizontal direction and the first mode resonance frequency is 11 kHz. A Finite Element Method (FEM) model is used to validate the measured sensitivity and resonance frequency. Good agreement between the model and the measurements is seen. 相似文献
63.
Nonresponse to surveys, which seems to plague work environment studies and studies of health care personnel in particular, may pose problems of generalizability and validity. The aim of this study was to provide an estimate of nonresponse error in a self-administered survey concerning the work environment of psychiatric health care personnel. A random sample of 10% of the original survey population (N?=?693) was selected to participate in a telephone follow-up of a postal survey that had a response rate of 51%. There were no differences between the responders and nonresponders to the postal survey on the exposure or outcome variables. There was no evidence of nonresponse bias in this study, although recall bias may have been a problem. In those cases in which generalizability is deemed important, it is recommended that nonresponse studies be regularly carried out when response rates are less than 100%. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
64.
Mads Nielsen Peter Johansen Andrew D. Jackson Benny Lautrup Søren Hauberg 《Journal of Mathematical Imaging and Vision》2008,31(2-3):221-231
A Brownian motion model in the group of diffeomorphisms has been introduced as inducing a least committed prior on warps. This prior is source-destination symmetric, fulfills a natural semi-group property for warps, and with probability 1 creates invertible warps. Using this as a least committed prior, we formulate a Partial Differential Equation for obtaining the maximally likely warp given matching constraints derived from the images. We solve for the free boundary conditions, and the bias toward smaller areas in the finite domain setting. Furthermore, we demonstrate the technique on 2D images, and show that the obtained warps are also in practice source-destination symmetric and in an example on X-ray spine registration provides extrapolations from landmark point superior to those of spline solutions. 相似文献
65.
Digital dermatitis is a serious problem in dairy production in many countries. In many settings, it is important to evaluate the digital dermatitis status of individual cows or an entire dairy herd. Such an evaluation has traditionally been done in a hoof trimming chute. An evaluation in the milking parlor can take place without disturbing the cows to a large extent, it can be done using less labor compared with an evaluation in a hoof trimming chute, and is cheaper than using a chute. The objective was to evaluate the sensitivity and specificity of a rapid screening method for digital dermatitis in the milking parlor, without using any specialized tools and taking approximately 15 s/cow. All lactating cows in 3 commercial Danish dairy herds were included. Cows were first scored for the presence of digital dermatitis during milking and the next day all cows were scored during hoof trimming. A 6-point nominal scoring system based on a visual inspection of the digital dermatitis lesions was used. For the analysis, the scores were dichotomized (digital dermatitis positive or digital dermatitis negative). Additionally, lesions were classified as small (diameter ≤ 2 cm) or large (diameter >2 cm). Sensitivity and specificity were calculated using observations from the hoof trimming chute as the “gold standard” and observations during milking as the diagnostic test. Relatively large variation was found between herds with an overall sensitivity of 0.65 (95% confidence interval: 0.59 to 0.72) and a specificity of 0.84 (0.81 to 0.87). The sensitivity increased to 0.69 (0.62 to 0.76), when only large lesions were assessed. The method has several advantages compared with evaluation in a chute and may be a useful tool in the daily hoof health management in dairy herds. 相似文献
66.
Hans Erhorn Tomasz Mroz Ove Mørck Fritz Schmidt Lorenz Schoff Kirsten Engelund Thomsen 《Energy and Buildings》2008,40(4):419-428
Educational buildings such as kindergartens, schools and universities display many similar design, operation and maintenance features in most countries. The two most noteworthy similarities amongst these building types are the high energy consumption and the necessity for retrofitting many buildings within this sector. However, studies have shown that during retrofit, energy saving measures are only rarely applied, because the decision-makers lack knowledge of investments and the efficiency of potential energy saving measures. The main goal of the International Energy Agency ECBCS Annex 36 is to provide the educational building decision-makers with sufficient data, information and tools to improve their learning and teaching environments by improving the energy efficiency of their buildings. 相似文献
67.
A 27-year-old woman was admitted with an abdominal mass in the right hypochondrium. Ultrasound, intravenous urography and scintigraphy revealed a giant non-functioning hydronephrosis. Because she refused surgery, a percutaneous aspiration with instillation of doxycycline was performed. One year thereafter, the patient was still without recurrence of any symptoms or hydronephrosis. 相似文献
68.
Van Gils M. Rosenfalck A. White S. Prior P. Gade J. Senhadji L. Thomsen C. Ghosh I.R. Longford R.M. Jensen K. 《IEEE engineering in medicine and biology magazine》1997,16(6):56-63
Methods for analyzing and displaying EEG signals are discussed. The increasing availability and affordability of powerful computer equipment makes possible the use of ever more sophisticated signal processing techniques, which extract relevant (but not readily discernible) information from long-term EEG recordings and can easily identify important features in the EEG. Whether these techniques are actually taken up in clinical practice is heavily dependent on how well they match clinical requirements. This article concentrates on requirements set in the context of long-term recordings in the ICU that demand the ability to process short-term discrete events as well as long-term trend information. A huge range of potentially useful signal processing techniques exists. This article illustrates the value of some of these techniques for ICU signals using the EEG recordings collected during the IMPROVE project 相似文献
69.
We compare the performance of a digital receiver operating with both a fixed and adaptive decision threshold in response to gain transients arising from network operation of an optically gain-clamped erbium-doped fiber amplifier. An optical burst switching link, based on a recirculating transmission loop, is used to study the effect of transients accumulated across a number wavelength-routing nodes linked by amplified fiber spans where bursts are added and dropped at each node. The use of an adaptive threshold reduces the amount of optical feedback required by a factor of 6 and, in some cases, allows for unclamped operation. 相似文献
70.
A.E. Lewis J. Nathoo K. Thomsen H.J. Kramer G.J. Witkamp S.T. Reddy D.G. Randall 《Chemical Engineering Research and Design》2010
Complex, hypersaline brines originating from the mining and extractive metallurgical industries have the potential to be treated using Eutectic Freeze Crystallization (EFC). Although EFC has been shown to be effective in separating a single salt and water, it has yet to be applied to the complex hypersaline brines that are typical of reverse osmosis retentates in South Africa. This paper focuses on the application of EFC for the purification of a typical brine containing high levels of sodium, chlorine, sulphate and ammonia that cannot be achieved with other separation techniques. The presence of ammonia prevents the application of membrane technology to treat the brine, leaving only cooling or evaporation as other possible options. Evaporation produces a mixed salt that requires further treatment. Modelling tools were applied to describe the phase behaviour of the complex saline systems under different process conditions and were experimentally validated. The results showed that Eutectic Freeze Crystallization could be used to selectively recover the sodium as a sodium sulphate salt. The simulation tools were especially useful in the design and optimisation of the process. 相似文献