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排序方式: 共有2034条查询结果,搜索用时 15 毫秒
91.
Wolfgang Tobias 《Welding International》2013,27(2):192-193
Abstract The existing technologies of hot tool butt and high temperature welding are changing with the additives and fillers which are being added to thermoplastics to improve their properties. This necessitates modification of the welding apparatus. The details are discussed using PVC-VM and chalk-filled polypropylene as examples. 相似文献
92.
Davide Bilò Hans-Joachim Böckenhauer Dennis Komm Richard Královič Tobias Mömke Sebastian Seibert Anna Zych 《Algorithmica》2011,61(2):227-251
A reoptimization problem describes the following scenario: given an instance of an optimization problem together with an optimal
solution for it, we want to find a good solution for a locally modified instance. 相似文献
93.
Sagar S Pandit Ram S Kulkarni Hemangi G Chidley Ashok P Giri Keshav H Pujari Tobias G Köllner Jörg Degenhardt Jonathan Gershenzon Vidya S Gupta 《Journal of the science of food and agriculture》2009,89(12):2071-2081
BACKGROUND: Volatile blends of five developing and five ripening stages of mango (Mangifera indica L. cv. Alphonso) were investigated along with those of flowers and leaves. Raw and ripe fruits of cv. Sabja were also used for comparison. RESULTS: A total of 55 volatiles belonging to various chemical classes such as aldehydes, alcohols, mono‐ and sesquiterpene hydrocarbons, lactones and furanones were identified. In all Alphonso tissues monoterpenes quantitatively dominated, with 57–99% contribution; in particular, (Z)‐ocimene was found in the highest amount. Ripeness was characterized by the de novo appearance of lactones and furanones in the blend of monoterpenes. Sabja was distinguished by the abundance of monoterpene hydrocarbons in the raw fruit, and that of sesquiterpene hydrocarbons and their derivatives in the ripe stage. CONCLUSION: Various stages of the Alphonso fruit during transition from flower to ripe fruit are characterized by unique volatile signatures that are distinguished from each other by the qualitative and quantitative appearance of different volatile compounds. Thus volatiles can be highly informative markers while studying the development and ripening of mango. Copyright © 2009 Society of Chemical Industry 相似文献
94.
Andreas Bortfeldt Tobias Winter 《International Transactions in Operational Research》2009,16(6):685-713
Given a set of rectangular pieces and a rectangular container, the two-dimensional knapsack problem (2D-KP) consists of orthogonally packing a subset of the pieces within the container such that the sum of the values of the packed pieces is maximized. If the value of a piece is given by its area, the objective is to maximize the covered area of the container. A genetic algorithm (GA) is proposed addressing the guillotine case of the 2D-KP as well as the non-guillotine case. Moreover, an orientation constraint may optionally be taken into account and the given piece set may be constrained or unconstrained. The GA is subjected to an extensive test using well-known benchmark instances. Compared with recently published methods, the GA yields competitive results. 相似文献
95.
Thomas Beer Tobias Meisen Rudolf Reinhard Sergey Konovalov Daniel Schilberg Sabina Jeschke Torsten Kuhlen Christian Bischof 《Production Engineering》2011,5(4):383-391
Computational simulations are used for the optimization of production processes in order to significantly reduce the need
for costly experimental optimization approaches. Yet individual simulations can rarely describe more than a single production
step. A set of simulations has to be coupled to each other to form a contiguous representation of a process chain. Eventually,
simulated results have to be analyzed by domain experts to gather insight from the preformed computations. In this paper,
we propose an IT infrastructure and software tools that aim at a rather non-intrusive way of coupling resources and domain
expert’s knowledge to enable the collaborative setup, execution and analysis of distributed simulation chains. We illustrate
the approach in the domain of materials processing. Beyond means originating from the domain of GRID computing for resource
management, a data integration component assures semantic data integrity between the simulation steps and stores simulation
data in an application independent way. Thus, we can transform this data into native formats for each simulation tool, and
finally into a format that allows for contiguous visualizations and an intuitive, comprehensive analysis of complete simulated
process chains. 相似文献
96.
The (socio-)psychological concepts of individual aspiration for conformity and consistency are integrated into the rational choice framework. By using this integrative approach, it is shown that, after a shock, the aspiration for conformity results in a steady state that deviates from the homo oeconomicus's behavior toward the consumption of the peer group, whereas the aspiration for consistency leads to the result that the steady-state consumption is not reached at once. With the combination of these effects, a new consumption path is derived. After a shock, the individual consumption converges step by step to the new steady-state consumption. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
97.
Schnitzler H Fröhlich U Boley TK Clemen AE Mlynek J Peters A Schiller S 《Applied optics》2002,41(33):7000-7005
We present a novel approach for the generation of higly frequency-stable, widely tunable, single-frequency cw UV light that is suitable for high-resolution spectroscopy. Sum-frequency generation (SFG) of two solid-state sources with a single cavity resonant for both fundamental waves is employed. Using a highly stable, narrow-linewidth frequency-doubled cw Nd:YAG laser as a master laser and slaving to it the SFG cavity and the other fundamental wave from a Ti:sapphire laser, we generate UV radiation of 33-mW output power around 313 nm. Alternatively, we use a diode laser instead of the Ti:sapphire laser and produce an output power of 2.1 mW at 313 nm. With both setups we obtain a continuous tunability of >15 GHz, short-term frequency fluctuations in the submegahertz range, a long-term frequency drift below 100 MHz/h, and stable operation for several hours. The theory of optimized doubly resonant SFG is also given. 相似文献
98.
Tobias Hanning René Schöne Georg Pisinger 《Journal of Mathematical Imaging and Vision》2006,25(1):5-23
In this article we present an approach to the segmentation problem by a piecewise approximation of the given image with continuous functions. Unlike the common approach of Mumford and Shah in our formulation of the problem the number of segments is a parameter, which can be estimated. The problem can be stated as: Compute the optimal segmentation with a fixed number of segments, then reduce the number of segments until the segmentation result fulfills a given suitability. This merging algorithm results in a multi-objective optimization, which is not only resolved by a linear combination of the contradicting error functions. To constrain the problem we use a finite dimensional vector space of functions in our approximation and we restrict the shape of the segments. Our approach results in a multi-objective optimization: On the one hand the number of segments is to be minimized, on the other hand the approximation error should also be kept minimal. The approach is sound theoretically and practically: We show that for L 2-images a Pareto-optimal solution exists and can be computed for the discretization of the image efficiently. 相似文献
99.
100.
Elimination of artifacts due to occlusion and discretization problems in image space blurring techniques 总被引:1,自引:0,他引:1
Brian A. Barsky Michael J. Tobias Derrick P. Chu Daniel R. Horn 《Graphical Models》2005,67(6):584-599
Traditional computer graphics methods render images that appear sharp at all depths. Adding blur can add realism to a scene, provide a sense of scale, and draw a viewer’s attention to a particular region of a scene. Our image-based blur algorithm needs to distinguish whether a portion of an image is either from a single object or is part of more than one object. This motivates two approaches to identify objects after an image has been rendered. We illustrate how these techniques can be used in conjunction with our image space method to add blur to a scene. 相似文献