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51.
First stage slurry reactor Fischer-Tropsch (FT) yield data from Mobil's two-step pilot plant operations for the DOE have been correlated using a modified Schulz-Flory approach but allowing for changes in the probability of chain growth, , at key product molecular weights. Triple values of are invoked to explain (1) the high methane yield and (2) the very broad molecular weight distribution of the wax fraction, as compared to (3) moderate values of 2 of between 0.79 and 0.85 for the C2–C20 hydrocarbons. Over this range, wax yields from 10 to 76 wt% are accommodated, at values of 3 from 0.90 to 0.98. The second break in the yield-molecular weight curve occurs at the carbon number where most of the component remains in the reactor as liquid rather than leaving as vapor product. It is assumed that this is a function of vapor-liquid equilibrium. The correlation has proven useful in developing a computer model of the FT synthesis loop which is part of a baseline design and economic study for DOE/PETC. 相似文献
52.
F Zolezzi A Forlino M Mottes M Valli A Sensi E Calzolari PF Pignatti G Cetta 《Canadian Metallurgical Quarterly》1995,6(3):268-271
The breast clinic in the university Hospital Kuala Lumpur was started in August 1993 to cater for the increasing number of women seeking treatment for breast complaints. A four-month survey carried out from January to April 1994 found that Chinese women are more "breast conscious" than Malay and Indian women. The majority of patients were in the reproductive age group. Benign breast diseases form the majority of cases of breast diseases seen. The pick-up rate for new cases of breast cancer was 3.1%. Fine needle aspiration biopsy had a 100% sensitivity during the four-month study, and was a quick method of obtaining a diagnosis. 相似文献
53.
Floor control refers to the need for coordinating activities occurred in synchronously cooperating applications shared among
collaborators. We address this for ubiquitous collaboration—the capability of multiple users to link together with disparate
access device anytime and anywhere. Floor control has been studied for years but most researchers focus on relaxed coordination
mechanisms with stationary devices that allow updates by any user on any object and resolve the uncoordinated updates. In
this paper we present a floor control mechanism, called XGSP-Floor, which implements a coordination mechanism at application
level for enabling users to consistently share the same resource in real time (synchronous collaboration) in ubiquitous collaboration
environment. The implementation platform on cell phone devices may not be new. But we believe the implementation and experiment
for XGSP-Floor on cell phone devices is a new challenge in ubiquitous collaboration environment even though the coordination
mechanism can intuitively impose a tremendous overhead in worst case. We also describe the results of the modeling of XGSP-Floor
and formal verification to prove the correctness of the modeling using Colored Petri Nets. We describe lessons learned and
discuss future work. 相似文献
54.
Charles W. Fox Ben Mitchinson Martin J. Pearson Anthony G. Pipe Tony J. Prescott 《Autonomous Robots》2009,26(4):223-239
Actuated artificial whiskers modeled on rat macrovibrissae can provide effective tactile sensor systems for autonomous robots.
This article focuses on texture classification using artificial whiskers and addresses a limitation of previous studies, namely,
their use of whisker deflection signals obtained under relatively constrained experimental conditions. Here we consider the
classification of signals obtained from a whiskered robot required to explore different surface textures from a range of orientations
and distances. This procedure resulted in a variety of deflection signals for any given texture. Using a standard Gaussian
classifier we show, using both hand-picked features and ones derived from studies of rat vibrissal processing, that a robust
rough-smooth discrimination is achievable without any knowledge of how the whisker interacts with the investigated object.
On the other hand, finer discriminations appear to require knowledge of the target’s relative position and/or of the manner
in which the whisker contact its surface.
Electronic Supplementary Material The online version of this article () contains supplementary material, which is available to authorized users.
相似文献
Anthony G. Pipe |
55.
Dirk Fox 《Datenschutz und Datensicherheit - DuD》2008,32(5):348-350
Zusammenfassung Eine Kryptoanalyse des verbreiteten Mifare-Chips, der in ca. 85% aller kontaktlosen Chipkarten zum Einsatz kommt, wurde erstmalig
auf dem CCC-Jahreskongress am 28.12.2007 vorgestellt. Inzwischen wurden weitere Details bekannt — und der Angriff erheblich
verbessert. Mitte April 2008 stellten Forscher der Radboud Universiteit Nijmegen einen Kurzfilm in You-Tube ein, in dem sie
den erfolgreichen Angriff auf eine Campus-Zugangskarte zeigen.
Dirk Fox Gesch?ftsführer der Secorvo Security Consulting GmbH und Herausgeber der DuD. 相似文献
56.
57.
The per review system for the assessment of research proposals is widely respected by working scientists. Nevertheless two problems associated with the operation of this system by the US National Institutes of Health are identified. First the scientist has no control over which committee will review an application and it may be considered by a quite inappropriate group. Second analysis of the committee composition suggests that in some of the groups several members are not active scientists and therefore not the "peers" of the applicant. 相似文献
58.
Interactive Workspaces 总被引:1,自引:0,他引:1
We are rapidly entering a world in which people equip themselves with a small constellation of mobile devices and pass through environments rich in embedded technology. However, we are still a long way from harnessing the power of this technology in a way that seamlessly and invisibly assists users in their day-to-day activities. Bringing pervasive computing to maturity requires innovations in systems integration and human-computer interaction (HCI). To investigate these challenges, Stanford University's Interactive Workspaces project (http://iwork.stanford.edu/) is exploring team-based collaboration in technology-augmented environments. These workspaces are designed to allow groups of five to ten people to work together using computing and interaction devices on many scales. 相似文献
59.
This paper addresses the problem of building large-scale geometric maps of indoor environments with mobile robots. It poses the map building problem as a constrained, probabilistic maximum-likelihood estimation problem. It then devises a practical algorithm for generating the most likely map from data, along with the most likely path taken by the robot. Experimental results in cyclic environments of size up to 80 by 25 meter illustrate the appropriateness of the approach. 相似文献
60.
Presents the obituary for Robert A. Harper (1915-2004). Dr. Harper is noted for his contributions to the field of psychotherapy, particularly to the areas of marriage, family, and sex therapy. In addition, his expertise, good nature, and no-nonsense style made him a popular figure amongst his peers, who elected him to leadership positions in numerous professional organizations. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献