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31.
With the proliferation of macroergonomic field research, it is time to carefully examine how such research should be managed and implemented. We argue that the importance of attending to high-quality implementation of field research is equal to that of methodological rigor. One way to systematically manage the implementation process is to adopt a change management framework, wherein the research project is conceptualized as an instance of organization-level change. Consequently, principles for successful organization-level change from the literature on change management can be used to guide successful field research implementation. This paper briefly reviews that literature, deriving 30 principles of successful change management, covering topics such as political awareness, assembling the change team, generating buy-in, and management support. For each principle, corresponding suggestions for macroergonomic field research practice are presented. We urge other researchers to further develop and adopt frameworks that guide the implementation of field research. 相似文献
32.
Sibylle Gruber Joy Kreeft Peyton Bertram C. Bruce 《Computer Supported Cooperative Work (CSCW)》1994,3(3-4):247-269
Research in computer-supported writing has traditionally compared electronic communication with oral, face-to-face communication to identify the benefits and weaknesses of each, as if they entailed dichotomous choices. In this article, we challenge that view and argue instead that any form of communication and its educational usefulness is shaped by the situation in which it is used, the backgrounds and goals of the participants, the institutional and technological setup, and the intended purpose of the medium. Three modes of communication in one graduate course are examined — oral discussion, synchronous written discussion on a local area network, and asynchronous written postings on an email list set up for the class. It was found that patterns of participation, topic introduction, and topic development differed across the three communication modes, but that the three were interwoven with each other and embedded within the larger classroom context and forms of knowledge creation in the class. Thus, rather than examining different communication media separately, researchers interested in understanding computer-supported collaborative writing need to look at how different media are used to create a meta-medium, which is established by the discourse community involved. 相似文献
33.
A. A. Zhukov G. K. Perkins J. V. Thomas A. D. Caplin H. Küpfer T. Wolf 《Journal of Low Temperature Physics》1996,105(5-6):1105-1110
Using vector magnetic moment measurements, in twinned YBa2Cu3Oy single crystals we observe a nearly reversible Mab component of the magnetisation with sharp peaks in the dependence of Mab on the magnetic field H and angle between c-axis and magnetic field. The association of these features with twin boundaries is supported by geometrical arguments and by comparison with detwinned samples. For a crystal with a single dominant direction of twin boundaries, the initial slope of the Mab(H) and Mab() dependences corresponds closely to ideal shielding of the transverse H component, as expected for the fully-locked vortex state. The peak position, which is related to the locking angle, shows a close to linear Hp
–1 vs dependence, which corresponds to a fixed value of HL, the locking field. The influence of twins vanishes above a trapping angle T which shows rather weak temperature and magnetic field dependences; at 60K and 1T these parameters are oHL=27mT and T 10 °. 相似文献
34.
Hummel M Garth C Hamann B Hagen H Joy KI 《IEEE transactions on visualization and computer graphics》2010,16(6):1319-1328
Integral surfaces are ideal tools to illustrate vector fields and fluid flow structures. However, these surfaces can be visually complex and exhibit difficult geometric properties, owing to strong stretching, shearing and folding of the flow from which they are derived. Many techniques for non-photorealistic rendering have been presented previously. It is, however, unclear how these techniques can be applied to integral surfaces. In this paper, we examine how transparency and texturing techniques can be used with integral surfaces to convey both shape and directional information. We present a rendering pipeline that combines these techniques aimed at faithfully and accurately representing integral surfaces while improving visualization insight. The presented pipeline is implemented directly on the GPU, providing real-time interaction for all rendering modes, and does not require expensive preprocessing of integral surfaces after computation. 相似文献
35.
We propose two deterministic secure quantum communication protocols employing three-qubit GHZ-like states and five-qubit Brown states as quantum channels for secure transmission of information in units of two bits and three bits using multipartite teleportation schemes developed here. In these schemes, the sender’s capability in selecting quantum channels and the measuring bases leads to improved qubit efficiency of the protocols. 相似文献
36.
Gosink LJ Anderson JC Bethel EW Joy KI 《IEEE transactions on visualization and computer graphics》2008,14(6):1715-1722
The visualization and analysis of AMR-based simulations is integral to the process of obtaining new insight in scientific research. We present a new method for performing query-driven visualization and analysis on AMR data, with specific emphasis on time-varying AMR data. Our work introduces a new method that directly addresses the dynamic spatial and temporal properties of AMR grids that challenge many existing visualization techniques. Further, we present the first implementation of query-driven visualization on the GPU that uses a GPU-based indexing structure to both answer queries and efficiently utilize GPU memory. We apply our method to two different science domains to demonstrate its broad applicability. 相似文献
37.
Waters KW Co CS Joy KI 《IEEE transactions on visualization and computer graphics》2006,12(5):1275-1282
We present a novel approach to out-of-core time-varying isosurface visualization. We attempt to interactively visualize time-varying datasets which are too large to fit into main memory using a technique which is dramatically different from existing algorithms. Inspired by video encoding techniques, we examine the data differences between time steps to extract isosurface information. We exploit span space extraction techniques to retrieve operations necessary to update isosurface geometry from neighboring time steps. Because only the changes between time steps need to be retrieved from disk, I/O bandwidth requirements are minimized. We apply temporal compression to further reduce disk access and employ a point-based previewing technique that is refined in idle interaction cycles. Our experiments on computational simulation data indicate that this method is an extremely viable solution to large time-varying isosurface visualization. Our work advances the state-of-the-art by enabling all isosurfaces to be represented by a compact set of operations. 相似文献
38.
We consider a failure-prone manufacturing system with bursty demand arrivals. We prove that the hedging-point policy is optimal for this problem and provide analytical expressions to compute the hedging point. This allows us to compare our exact results to simpler approximations. We also show that our result leads to the solution for the constant demand rate problem, under an appropriate scaling of the demand process. We also provide a necessary and sufficient condition under which the just-in-time (JIT) policy is optimal for the case of linear, absolute value instantaneous cost 相似文献
39.
CS Walpole R Wrigglesworth S Bevan EA Campbell A Dray IF James KJ Masdin MN Perkins J Winter 《Canadian Metallurgical Quarterly》1993,36(16):2381-2389
Structural variants of the hydrophobic side chain ("C region") of the capsaicin molecule have been incorporated into a series of vanillylamides and vanillylthioureas. These compounds have been tested in an in vitro assay for agonism (45Ca2+ influx into dorsal root ganglia neurones), previously shown to be predictive of analgesic activity. The results of this study have established the requirement for a hydrophobic substituent of limited size (molar refractivity, MR, < 55) in order to obtain high potency. Combination of the information gained here about the "C-region" of the capsaicin molecule with the studies described in the preceding two papers provides a rational basis for the design of compounds of increased potency. 相似文献
40.