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81.
Joxan Jaffar Michael J. Maher Peter J. Stuckey Roland H. C. Yap 《New Generation Computing》1993,11(3-4):449-469
The presentation of constraints in a usable form is an essential aspect of Constraint Logic Programming (CLP) systems. It is needed both in the output of constraints, as well as in the production of an internal representation of constraints for meta-level manipulation. Typically, only a small subset \(\tilde x\) of the variables in constraints is of interest, and so an informal statement of the problem at hand is: given a conjunction \(c(\tilde x,\tilde y)\) of constraints, express the projection \(\exists \tilde y c(\tilde x,\tilde y)\) ofc onto \(\tilde x\) in the simplest form. In this paper, we consider the constraints of the CLP(R) system and describe the essential features of its projection module. One main part focuses on the well-known problem of projection inlinear arithmetic constraints. We start with a classical algorithm and augment it with a procedure for eliminating redundant constraints generated by the algorithm. A second part discusses projection of the other object-level constraints: equations over trees and nonlinear equations. The final part deals with producing a manipulable form of the constraints, which complicates the projection problem. 相似文献
82.
Roland Gerber 《电信纪事》1983,38(9-10):367-379
83.
Bernd Altmayer Klaus W. Eichhorn und Roland Plapp 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1982,175(3):172-174
Zusammenfassung Traubenmoste aus dem Weinanbaugebiet der Rheinpfalz wurden auf ihren Patulingehalt untersucht. Nach Extraktion und Reinigung wurde Patulin mit Hilfe der Hochleistungsflilssig- und Dünnschichtchromatographie bestimmt. Zur Extraktion des Patulins erwies sich die Verwendung von Extrelutsdulen als vorteilhaft. In 62% der untersuchten Proben (55) war kein Patulin nachweisbar, 22% enthielten weniger als 50 g, 16% mehr als 50 g Patulin pro Liter. Durch praxisübliche Mostschwefelung (100 mg Kaliumpyrosulîit/1) und Vergärung mit Hefen der GattungSaccharomyces konnte vorhandenes Patulin entfernt werden.
Analysis of patulin in grape juices and wine
Summary Grape juices from the wine-growing region of the palatinate Rheinpfalz were analysed for patulin. After extraction and purification patulin was determined by high performance liquid chromatography and thin layer chromatography. The use of Extrelut-columns for the extraction of patulin was found advantageous. 62% of the analysed samples (55) were free of patulin, 22% contained less than 50 g/l, 16% more than 50 g/l. By addition of sulfur dioxide to the must and fermentation withSaccharomyces sp. patulin could be removed from the samples.相似文献
84.
Christian Pruner Martin Fally Romano A. Rupp Roland P. May Jürgen Vollbrandt 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2006,560(2):598-605
Design and setup of an interferometer for cold and ultracold neutrons are described. As neutron optical components three holographically produced gratings are arranged in triple Laue geometry. The gratings are adjusted during their recording process in photosensitized polymer slabs once for ever. Employing this device we measured the coherence function of a cold neutron beam by means of interferometry. 相似文献
85.
86.
Roland Rüdiger 《Informatik-Spektrum》2003,13(3):406-409
Algorithmen für Quantenrechner wie
der Faktorisierungsalgorithmus von Shor lassen sich mittels
neuer Programmiersprachen formulieren, die neben konventionellen
auch über für Quantenrechner spezifische Sprachkonstrukte
verfügen. In Verbindung mit Simulatoren kann man so auch bereits
heute Programme für Quantenrechner entwickeln und
testen. 相似文献
87.
The repeated median line estimator is a highly robust method for fitting a regression line to a set of n data points in the plane. In this paper, we consider the problem of updating the estimate after a point is removed from or added to the data set. This problem occurs, e.g., in statistical online monitoring, where the computational effort is often critical. We present a deterministic algorithm for the update working in O(n) time and O(n2) space. 相似文献
88.
The flow control problem in multi-part failure prone manufacturing systems is considered. While computationnaly attractive, the near optimal controllers of Caramanis and Sharifnia, suffer from the drawback that the production capacity set must be approximated via a very restricted set of inscribed hypercubes, namely those for which a componentwise feasibility requirement is satisfied. Also, due to the completely decoupled nature of production along each component, utilization of the restricted capacity set is suboptimal. A class of capacity set incribed hypercube policies called simple maximal hedging (SMH) policies is introduced. In SMH policies production levels along the various components of the capacity set are coupled, the componentwise feasibility requirement is lifted, and there is no underutilization of production capacity if needed. In a p part types manufacturing system, for partwise additive cost functionals, it is shown that performance evaluation of a given SMH policy reduces to the analysis of p decoupled (fictitious) semi-Markovian machines. The machines are Markovianized via first passage-time analysis and a Padé approximants technique. Numerical optimization over the class of SMH policies in a sample manufacturing system indicates that their performance can come close to that of the optimal control. 相似文献
89.
Frey B Hartmann M Herrmann M Meyer-Pittroff R Sommer K Bluemelhuber G 《Microscopy research and technique》2006,69(2):65-72
High hydrostatic pressure (HHP) becomes more and more interesting for life science research, since it can be employed to inactivate various cells. To directly monitor "cells under pressure," the development of an optical high-pressure chamber is required. Therefore, an optical pressure chamber that can be used for up to 300 MPa was constructed. This chamber has already been described as a tool for in situ observation of dynamic changes of microscopic structures in bright field as well as phase contrast. In combination with an inverted microscope, we obtained brilliant microscopic color pictures with an optical resolution more than 0.56 microm. Here, we demonstrate the capabilities of the HHP cell, in combination with epifluorescence microscopy. Using a nonadherent human B-cell line (Raji, ATCC CCL 86), stained with the fluorescent dyes propidium iodide, Hoechst 33342, or dihexyloxacarbocyanine iodide, we were able to show that the system is suitable to perform fluorescence microscopic analyses, with pressures up to 300 MPa, with viable mammalian cells. 相似文献
90.