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排序方式: 共有791条查询结果,搜索用时 15 毫秒
21.
Niels Jørgensen 《Information Systems Journal》2001,11(4):321-336
Abstract. Software development in the FreeBSD project is incremental in the sense that a stream of contributions, including bugfixes and minor and major new features, go into a single branch in the repository, the development branch (or 'trunk'), and are required to preserve the software in a working state. This creates a succession of development releases, akin to the practice of frequent releasing argued by Eric S. Raymond in his essay 'The Cathedral and the Bazaar' to be the key to the success of Linux and other open source projects. The positive and negative impact of this approach is discussed based on a survey involving 72 project participants. On the positive side, the data indicate that it creates a highly motivating 'see bug, fix bug, see bug fixed in new release' life cycle, and helps integrate bugfixing with new development. On the negative side, the data indicates that the highly incremental model does not support the development of complex new features. 相似文献
22.
Barelli S Canellini G Thadikkaran L Crettaz D Quadroni M Rossier JS Tissot JD Lion N 《Proteomics. Clinical applications》2008,2(2):142-157
Protein oxidation mechanisms result in a wide array of modifications, from backbone cleavage or protein crosslinking to more subtle modifications such as side chain oxidations. Protein oxidation occurs as part of normal regulatory processes, as a defence mechanism against oxidative stress, or as a deleterious processes when antioxidant defences are overcome. Because blood is continually exposed to reactive oxygen and nitrogen species, blood proteomics should inherently adopt redox proteomic strategies. In this review, we recall the biochemical basis of protein oxidation, review the proteomic methodologies applied to analyse redox modifications, and highlight some physiological and in vitro responses to oxidative stress of various blood components. 相似文献
23.
Evaluation of Crop Models for Simulating and Optimizing Deficit Irrigation Systems in Arid and Semi-arid Countries Under Climate Variability 总被引:2,自引:2,他引:0
Sebastian?KlossEmail author Raji?Pushpalatha Kefasi?J.?Kamoyo Niels?Schütze 《Water Resources Management》2012,26(4):997-1014
The variability of fresh water availability in arid and semi-arid countries poses a serious challenge to farmers to cope with
when depending on irrigation for crop growing. This has shifted the focus onto improving irrigation management and water productivity
(WP) through controlled deficit irrigation (DI). DI can be conceived as a strategy to deal with these challenges but more
knowledge on risks and chances of this strategy is urgently needed. The availability of simulation models that can reliably
predict crop yield under the influence of soil, atmosphere, irrigation, and agricultural management practices is a prerequisite
for deriving reliable and effective deficit irrigation strategies. In this context, this article discusses the performance
of the crop models CropWat, PILOTE, Daisy, and APSIM when being part of a stochastic simulation-based approach to improve
WP by focusing primarily on the impact of climate variability. The stochastic framework consists of: (i) a weather generator
for simulating regional impacts of climate variability; (ii) a tailor-made evolutionary optimization algorithm for optimal
irrigation scheduling with limited water supply; and (iii) the above mentioned models for simulating water transport and crop
growth in a sound manner. The results present stochastic crop water production functions (SCWPFs) that can be used as basic
tools for assessing the impact on the risk for the potential yield due to water stress and climate variability. Example simulations
from India, Malawi, France and Oman are presented and the suitability of these crop models to be employed in a framework for
optimizing WP is evaluated. 相似文献
24.
Andreas L?cken Tobias Hesselmann Martin Pielot Niels Henze Susanne Boll 《Multimedia Systems》2012,18(1):15-31
Music is a fundamental part of most cultures. Controlling music playback has commonly been used to demonstrate new interaction
techniques and algorithms. In particular, controlling music playback has been used to demonstrate and evaluate gesture recognition
algorithms. Previous work, however, used gestures that have been defined based on intuition, the developers’ preferences,
and the respective algorithm’s capabilities. In this paper we propose a refined process for deriving gestures from constant
user feedback. Using this process every result and design decision is validated in the subsequent step of the process. Therefore,
comprehensive feedback can be collected from each of the conducted user studies. Along the process we develop a set of free-hand
gestures for controlling music playback. The situational context is analysed to shape the usage scenario and derive an initial
set of necessary functions. In a successive user study the set of functions is validated and proposals for gestures are collected
from participants for each function. Two gesture sets containing static and dynamic gestures are derived and analysed in a
comparative evaluation. The comparative evaluation shows the suitability of the identified gestures and allows further refinement.
Our results indicate that the proposed process, that includes validation of each design decision, improves the final results.
By using the process to identify gestures for controlling music playback we not only show that the refined process can successfully
be applied, but we also provide a consistent gesture set that can serve as a realistic benchmark for gesture recognition algorithms. 相似文献
25.
Anderson John R.; Taatgen Niels A.; Byrne Michael D. 《Canadian Metallurgical Quarterly》2005,31(4):749
E. Hazeltine, D. Teague, and R. B. Ivry (see record 2002-02997-003) have presented data that have been interpreted as evidence against a central bottleneck. This article describes simulations of their Experiments 1 and 4 in the ACT-R cognitive architecture, which does possess a central bottleneck in production execution. The simulation model is capable of accounting for the emergence of near-perfect timesharing in Experiment 1 and the detailed data on the distribution of response times from Experiment 4. With practice, the central bottleneck in ACT-R will be reduced to a maximum of 50 ms (1 production cycle) and can often be much less, depending on timing of stages and variability in their times. The authors also show, with a mathematical analysis of E. Hazeltine et al.'s Experiment 2, that the expected dual costs for these kinds of highly practiced tasks will be small in many circumstances, often under 10 ms. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
26.
Mikael B. Skov Jesper Kjeldskov Jeni Paay Niels Husted Jacob Nørskov Kenneth Pedersen 《Pervasive and Mobile Computing》2013,9(2):216-227
Some movements within modern architecture particularly emphasise the importance of matching buildings to their surroundings. However, practicing such “contextual architecture” is highly challenging and typically not something the future inhabitants of a building are well equipped for participating in. This paper explores the potentials of using mobile phone technology for facilitating such client participation in the parts of an architecture process that take place on the building site. For this we introduce ArchiLens, a mobile system for interactive on-site 3D visualisation of houses, and findings from a field study with 40 participants in the process of building or modifying their home. The study showed that using the system helped evoke people’s imagination of the look and feel of their future house, and envision it in context. This enabled them to participate more closely in the design process on-site by iteratively reviewing design alternatives and exploring, for example, other placements and materials. 相似文献
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29.
Denitza Denkova Niels Verellen Alejandro V. Silhanek Pol Van Dorpe Victor V. Moshchalkov 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(10):1959-1966
The design of many promising, newly emerging classes of photonic metamaterials and subwavelength confinement structures requires detailed knowledge and understanding of the electromagnetic near‐field interactions between their building blocks. While the electric field distributions and, respectively, the electric interactions of different nanostructures can be routinely measured, for example, by scattering near‐field microscopy, only recently experimental methods for imaging the magnetic field distributions became available. In this paper, we provide direct experimental maps of the lateral magnetic near‐field distributions of variously shaped plasmonic nanoantennas by using hollow‐pyramid aperture scanning near‐field optical microscopy (SNOM). We study both simple plasmonic nanoresonators, such as bars, disks, rings and more complex antennas. For the studied structures, the magnetic near‐field distributions of the complex resonators have been found to be a superposition of the magnetic near‐fields of the individual constituting elements. These experimental results, explained and validated by numerical simulations, open new possibilities for engineering and characterization of complex plasmonic antennas with increased functionality. 相似文献
30.
David Aili Qingfeng Li Erik Christensen Jens Oluf Jensen Niels J Bjerrum 《Polymer International》2011,60(8):1201-1207
Phosphoric acid‐doped polybenzimidazole (PBI) has been suggested as a promising electrolyte for proton exchange membrane fuel cells operating at temperatures up to 200 °C. This paper describes the development of a crosslinking procedure for PBI membranes by post‐treatment with divinylsulfone. The crosslinking chemistry was studied and optimized on a low‐molecular‐weight model system and the results were used to optimize the crosslinking conditions of PBI membranes. The crosslinked membranes were characterized with respect to chemical and physiochemical properties, showing improved mechanical strength and oxidative stability compared with their linear analogues. Fuel cell tests were further conducted in order to demonstrate the feasibility of the crosslinked membranes. Copyright © 2011 Society of Chemical Industry 相似文献