4,325 research outputs found
Numerical study on diverging probability density function of flat-top solitons in an extended Korteweg-de Vries equation
We consider an extended Korteweg-de Vries (eKdV) equation, the usual
Korteweg-de Vries equation with inclusion of an additional cubic nonlinearity.
We investigate the statistical behaviour of flat-top solitary waves described
by an eKdV equation in the presence of weak dissipative disorder in the linear
growth/damping term. With the weak disorder in the system, the amplitude of
solitary wave randomly fluctuates during evolution. We demonstrate numerically
that the probability density function of a solitary wave parameter
which characterizes the soliton amplitude exhibits loglognormal divergence near
the maximum possible value.Comment: 8 pages, 4 figure
Occupy: 'struggles for the common or an 'anti-politics of dignity? Reflections on Hardt and Negri and John Holloway
This article provides a critical examination of Michael Hardt and Antonio Negri’s and John Holloway’s theory of revolutionary subjectivity, and does so by applying their theories to the Occupy movement of 2011. Its central argument is that one should avoid collapsing ‘autonomist’ and ‘open’ Marxism, for whilst both approaches share Tronti’s (1979) insistence on the constituent role of class struggle, and also share an emphasis on a prefigurative politics which engages a non-hierarchical and highly participatory politics, there nevertheless remain some significant differences between their approaches. Ultimately, when applied to Occupy Movement whilst their theory isn’t entirely unproblematic, I will argue that Hardt and Negri’s ‘autonomist’ approach offers the stronger interpretation, due mainly to their revised historical materialism
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'Open Marxism' against and beyond the 'Great Enclosure'? Reflections on How (Not) to Crack Capitalism
The main purpose of this article is to provide an in-depth discussion of John Holloway’s recent book, Crack Capitalism. To this end, the paper offers a detailed account of the key strengths and weaknesses of Holloway’s version of ‘open Marxism’. The analysis is divided into two parts. The first part focuses on six significant strengths of Crack Capitalism: (1) its insistence upon the importance of autonomous forms of agenda-setting for both individual and collective emancipation; (2) its emphasis on the ordinary constitution of social struggles; (3) its fine-grained interpretation of the socio-ontological conditions underlying human agency; (4) its processual conception of radical social transformation; (5) its recognition of the elastic, adaptable, and integrative power of capitalism; and (6) its proposal for an alternative critical theory, commonly known as ‘open Marxism’ or ‘autonomous Marxism’. The second part of the study examines the principal weaknesses of Crack Capitalism: (1) the counterproductive implications of the preponderance of negativity, owing to a one-sided concern with critique, cracks, and crises; (2) conceptual vagueness; (3) an overuse of poetic and metaphorical language; (4) the absence of a serious engagement with the question of normativity; (5) a lack of substantive evidence; (6) a residual economic reductionism; (7) a simplistic notion of gender; (8) the continuing presence of various problematic ‘isms’; (9) the misleading distinction between ‘doing’ and ‘labour’; (10) a reductive understanding of capitalism; (11) an unrealistic view of society; and (12) socio-ontological idealis
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Evaluation of Corba for use in distributed control systems
The Common Object Request Broker Architecture (CORBA)-based Simulator was a Laboratory Directed Research and Development (LDRD) project that applied simulation techniques to explore critical questions about advanced distributed control system architectures. A three-prong approach comprised of a study of object-oriented distribution tools, computer network modeling, and simulation of key control system scenarios was used in the LDRD project. This input report describes the first of the three approaches Ñ the study of object-oriented distribution tools together with measurements, and predictions of use within the National Ignition Facility (NIF) and some aspects of CORBA which remain to be resolved. For the ICCS, the completeness of suitable functionality, the speed of performance and utilization of machine and network resources, and the developing nature of the commercial CORBA products themselves, presented a certain risk. This LDRD thus evaluated CORBA in general, and a particular implementation, to determine its features, performance, and scaling properties, and to optimize its use within the ICCS. Both UNIX and real-time operating systems were studied
Earth Radiation Budget Experiment (ERBE) scanner instrument anomaly investigation
The results of an ad-hoc committee investigation of in-Earth orbit operational anomalies noted on two identical Earth Radiation Budget Experiment (ERBE) Scanner instruments on two different spacecraft busses is presented. The anomalies are attributed to the bearings and the lubrication scheme for the bearings. A detailed discussion of the pertinent instrument operations, the approach of the investigation team and the current status of the instruments now in Earth orbit is included. The team considered operational changes for these instruments, rework possibilities for the one instrument which is waiting to be launched, and preferable lubrication considerations for specific space operational requirements similar to those for the ERBE scanner bearings
Growth and Development of F-1 (Brahman x Hereford) Heifers Under Various Short-Term Grazing Pressures
Last updated: 6/1/200
Highly supersonic motions within the outer features of the Eta Carinae nebulosity
Spatially resolved H and [N{\sc ii}] line profiles have been obtained
over striking features in the outer regions of the Eta Carinae nebula. The
highly irregular outer `shell' of low ionization, [N{\sc ii}] bright, knots has
been shown to exhibit radial velocities between -1200 and +300 km/s with
respect to the systemic radial velocity, over its perimeter. Furthermore,
several knots have been found which appear to emit only in the H line
with radial velocities up to -1450 km/s.
However, the most intriguing features are a narrow `spike' that projects
through this outer shell and a faint `arc' of emission that extends well beyond
it. The `spike', which exhibits a change of radial velocity along its length,
could be a narrow collimated jet with an outflow velocity of > 1000 km/s. In
one interpretation the `arc' is modelled by a conical outflow and mechanisms
for generating [N{\sc ii}] emission from highly supersonic gas are also
discussed.Comment: MNRAS style file, 6 pages. 7 eps figures are not included but are
available individually at http://axp2.ast.man.ac.uk:8000/Preprints.htm
Validation of a Multivariate Serum Profile for Epithelial Ovarian Cancer Using a Prospective Multi-Site Collection
In previous studies we described the use of a retrospective collection of ovarian cancer and benign disease samples, in combination with a large set of multiplexed immunoassays and a multivariate pattern recognition algorithm, to develop an 11-biomarker classification profile that is predictive for the presence of epithelial ovarian cancer. In this study, customized, Luminex-based multiplexed immunoassay kits were GMP-manufactured and the classification profile was refined from 11 to 8 biomarkers (CA-125, epidermal growth factor receptor, CA 19-9, C-reactive protein, tenascin C, apolipoprotein AI, apolipoprotein CIII, and myoglobin). The customized kits and the 8-biomarker profile were then validated in a double-blinded manner using prospective samples collected from women scheduled for surgery, with a gynecologic oncologist, for suspicion of having ovarian cancer. The performance observed in model development held in validation, demonstrating 81.1% sensitivity (95% CI 72.6 – 87.9%) for invasive epithelial ovarian cancer and 85.4% specificity (95% CI 81.1 – 88.9%) for benign ovarian conditions. The specificity for normal healthy women was 95.6% (95% CI 83.6 – 99.2%). These results have encouraged us to undertake a second validation study arm, currently in progress, to examine the performance of the 8-biomarker profile on the population of women not under the surgical care of a gynecologic oncologist
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Becoming Sociological: Disciplinarity and a Sense of ‘Home’
This short reflective piece uses the concept of ‘home’ to explore sociology as an intellectual and disciplinary pursuit. Drawing on autobiographical reflections and ethnographic study of sociology writing, I consider some of the trajectories of academics into sociology and what these tell us about the discipline itself. In light of increasing incursions by audit culture and marketisation of academia, Holmwood has drawn attention to a lack of clear internal identity as being ‘sociology’s misfortune’ – that sociology loses out, and is weakened by lacking theories and methodologies specific to the discipline. This essay takes a more optimistic view of sociology’s position, and instead argues that it is this very ambiguity which keeps the discipline a lively and vital space for explorations of the social
Si3AlP: A new promising material for solar cell absorber
First-principles calculations are performed to study the structural and
optoelectronic properties of the newly synthesized nonisovalent and
lattice-matched (Si2)0.6(AlP)0.4 alloy [T. Watkins et al., J. Am. Chem. Soc.
2011, 133, 16212.] We find that the ordered CC-Si3AlP with a basic unit of one
P atom surrounded by three Si atoms and one Al atom is the most stable one
within the experimentally observed unit cell.1 Si3AlP has a larger fundamental
band gap and a smaller direct band gap than Si, thus it has much higher
absorption in the visible light region. The calculated properties of Si3AlP
suggest that it is a promising candidate for improving the performance of the
existing Si-based solar cells. The understanding on the stability and band
structure engineering obtained in this study is general and can be applied for
future study of other nonisovalent and lattice-matched semiconductor alloys
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