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71.
We prove a general monotonicity result about Nash flows in directed networks, which generalizes earlier results and can be
used for the design of truthful mechanisms in the setting where each edge of the network is controlled by a different selfish agent, who incurs costs when her edge
is used. 相似文献
72.
Optimal design applications are often modeled by using categorical variables to express discrete design decisions, such as
material types. A disadvantage of using categorical variables is the lack of continuous relaxations, which precludes the use
of modern integer programming techniques. We show how to express categorical variables with standard integer modeling techniques,
and we illustrate this approach on a load-bearing thermal insulation system. The system consists of a number of insulators
of different materials and intercepts that minimize the heat flow from a hot surface to a cold surface. Our new model allows
us to employ black-box modeling languages and solvers and illustrates the interplay between integer and nonlinear modeling
techniques. We present numerical experience that illustrates the advantage of the standard integer model. 相似文献
73.
74.
75.
Chest compression is a vital part of cardiopulmonary resuscitation (CPR). This paper demonstrates how the compression depth can be estimated using the principles of inertia navigation. The proposed method uses accelerometer sensors, one placed on the patient's chest, the other beside the patient. The acceleration-to-position conversion is performed using discrete-time digital signal processing (DSP). Instability problems due to integration are combated using a set of boundary conditions. The proposed algorithm is tested on a mannequin in harsh environments, where the patient is exposed to external forces as in a boat or car, as well as improper sensor/patient alignment. The overall performance is an estimation depth error of 4.3 mm in these environments, which is reduced to 1.6 mm in a regular, flat-floor controlled environment. 相似文献
76.
Bühling S Wyrowski F 《Journal of the Optical Society of America. A, Optics, image science, and vision》2002,19(12):2414-2423
Diffractive beam-splitting elements are typically designed for replicating beams on positions belonging to an equidistant grid in the spatial spectrum. The parameter of the output grid follows directly from the period of the beam-splitter transmission through the grating equation. Our objective is to develop design strategies allowing a more accurate positioning of the replicated beams. Issues occurring when the output grid parameter is decreased below the output beam width are discussed and shown to be avoidable. Furthermore, a design algorithm is introduced, which permits an arbitrary positioning of the replicated beams. This algorithm is constructed for high computational efficiency by utilizing fast Fourier transform operations in the major part of its iterations. 相似文献
77.
Problem analysis is an important, but mainly neglected part of the problem‐solving process. The theory of inventive problem solving (TRIZ) offers an instrument called function analysis to conduct problem analysis, which is especially useful for exploring a problem. This process is based on an idea applied in different creativity techniques, saying that behind one problem statement many problem formulations may occur, which allows for evaluation and selection of those problem formulations before looking for problem solutions. The application of function analysis as a tool for teams is recommended for a number of reasons. In so doing so, two main questions arise: (i) Should function analysis be used with the help of an external moderator? and: (ii) Should it be applied with currently available special software? After introducing the basics of function analysis this article provides key findings deducted from an experiment addressing these questions. An important result is the remarkable learning effect, which occurs while using function analysis in teams. By applying function analysis in R&D, companies will be able to get deeper and team‐based problem explorations, which may lead to maturing problem solutions. 相似文献
78.
The dynamic programming solution offered is of complexity O(n2) and is a significant improvement over the implicit enumeration procedure previously suggested by Arora and Rana in an article in the September 1980 issue of TRANSACTIONS. 相似文献
79.
Löfstedt C Zhu J Kozlov MV Buda V Jirle EV Hellqvist S Löfqvist J Plass E Franke S Francke W 《Journal of chemical ecology》2004,30(3):643-658
Under an artificial light:dark cycle, females of Lampronia capitella were observed calling, with extended terminal abdominal segments, during the first 2 hr of the photoperiod. Extracts of terminal abdominal segments from females elicited large electroantennographic responses from male antennae. Gas chromatography with electroantennographic detection revealed three active peaks. Based on comparison of retention times and mass spectra of synthetic standards, these compounds were identified as (Z,Z)-9,11-tetradecadienol and the corresponding acetate and aldehyde. The electroantennographic activity of the four geometric isomers of all three compounds was investigated, and the respective (Z,Z)-isomer was found to be the most active in all cases. Aldehydes generally elicited larger antennal responses than alcohols, whereas acetates were the least active compounds. A subtractive trapping assay in the field, based on a 13:26:100 micrograms mixture of (Z,Z)-9,11-tetradecadienal, (Z,Z)-9,11-tetradecadienyl acetate, and (Z,Z)-9,11-tetradecadienol confirmed that all three compounds are pheromone components. Subtraction of (Z,Z)-9,11-tetradecadienol from the blend completely eliminated its attractiveness, whereas the other two-component blends showed reduced activity. This is the first pheromone identification from the monotrysian superfamily Incurvarioidea, confirming that the common pheromones among ditrysian moths (long-chain fatty acid derivatives comprising alcohols, acetates, and aldehydes with one or more double bonds) is not an autapomorphy of Ditrysia, but a synapomorphy of the more advanced heteroneuran lineages. 相似文献
80.