5,764 research outputs found
Academic Panel: Can Self-Managed Systems be trusted?
Trust can be defined as to have confidence or faith in; a form of reliance or certainty based on past experience; to allow without fear; believe; hope: expect and wish; and extend credit to. The issue of trust in computing has always been a hot topic, especially notable with the proliferation of services over the Internet, which has brought the issue of trust and security right into the ordinary home. Autonomic computing brings its own complexity to this. With systems that self-manage, the internal decision making process is less transparent and the âintelligenceâ possibly evolving and becoming less tractable. Such systems may be used from anything from environment monitoring to looking after Granny in the home and thus the issue of trust is imperative. To this end, we have organised this panel to examine some of the key aspects of trust. The first section discusses the issues of self-management when applied across organizational boundaries. The second section explores predictability in self-managed systems. The third part examines how trust is manifest in electronic service communities. The final discussion demonstrates how trust can be integrated into an autonomic system as the core intelligence with which to base adaptivity choices upon
A NuSTAR observation of the fast symbiotic nova V745 Sco in outburst
The fast recurrent nova V745 Sco was observed in the 3-79 keV X-rays band
with NuSTAR 10 days after the optical discovery. The measured X-ray emission is
consistent with a collisionally ionized optically thin plasma at temperature of
about 2.7 keV. A prominent iron line observed at 6.7 keV does not require
enhanced iron in the ejecta. We attribute the X-ray flux to shocked
circumstellar material. No X-ray emission was observed at energies above 20
keV, and the flux in the 3-20 keV range was about 1.6 10 erg
cm s. The emission measure indicates an average electron density
of order of 10 cm.
The X-ray flux in the 0.3-10 keV band almost simultaneously measured with
Swift was about 40 times larger, mainly due to the luminous central supersoft
source emitting at energy below 1 keV. The fact that the NuSTAR spectrum cannot
be fitted with a power law, and the lack of hard X-ray emission, allow us to
rule out Comptonized gamma rays, and to place an upper limit of the order of
10 erg cm s on the gamma-ray flux of the nova on the
tenth day of the outburst.Comment: in press in Monthly Notices of the Royal Astronomical Society, 201
Glancing Back at The Camelâs Hump: An Interpretative Phenomenological Analysis of Saudi Family Therapistsâ Dual Epistemologies
Since family therapy was brought only recently to Saudi Arabia, studies exploring the field in this context are few. This dissertation will be the first to focus on the self of the Saudi Arabian family therapist (SAFT). In particular, it will be the first to pay close attention to SAFTsâ ways of dealing with the differing and, perhaps, incompatible epistemologies of Saudi culture and religion on one side, and systemic thinking and family therapy on the other. This study seeks to shed a phenomenological light on what informs SAFTs and what influences their work. Using interpretative phenomenological analysis (IPA), I interviewed seven SAFTs, identifying the challenges they encounter as they undertake their practice, and clarifying how these therapists are adapting Western knowledge vis-Ă -vis the Saudi culture. An old saying in Arabic conveys the self-reflective challenge of examining epistemological assumptions. We say âa camel canât look at its own hump.â This dissertation is an attempt to at least steal a glance at it
Business to business online revenue management.
With the emergence of the Internet, electronic commerce (e-commerce), revenue management and especially applications that combine both are becoming increasingly an area of innovation for service industries. E-commerce has introduced efficiencies across the service chain and it has allowed improvements to take place within and across organizations. Revenue management when combined with ecommerce and done online not only improves resource management but it can be used as a strategic tool to gain competitive advantage. This chapter examines the current approaches and future trends in these very exciting and promising areas
Fluctuation relations for heat engines in time-periodic steady states
A fluctuation relation for heat engines (FRHE) has been derived recently. In
the beginning, the system is in contact with the cooler bath. The system is
then coupled to the hotter bath and external parameters are changed cyclically,
eventually bringing the system back to its initial state, once the coupling
with the hot bath is switched off. In this work, we lift the condition of
initial thermal equilibrium and derive a new fluctuation relation for the
central system (heat engine) being in a time-periodic steady state (TPSS).
Carnot's inequality for classical thermodynamics follows as a direct
consequence of this fluctuation theorem even in TPSS. For the special cases of
the absence of hot bath and no extraction of work, we obtain the integral
fluctuation theorem for total entropy and the generalized exchange fluctuation
theorem, respectively. Recently microsized heat engines have been realized
experimentally in the TPSS. We numerically simulate the same model and verify
our proposed theorems.Comment: 9 page
Spectral Changes in the Hyperluminous Pulsar in NGC 5907 as a Function of Super-Orbital Phase
We present broad-band, multi-epoch X-ray spectroscopy of the pulsating
ultra-luminous X-ray source (ULX) in NGC 5907. Simultaneous XMM-Newton and
NuSTAR data from 2014 are best described by a multi-color black-body model with
a temperature gradient as a function of accretion disk radius significantly
flatter than expected for a standard thin accretion disk (T(r) ~ r^{-p}, with
p=0.608^{+0.014}_{-0.012}). Additionally, we detect a hard power-law tail at
energies above 10 keV, which we interpret as being due to Comptonization. We
compare this observation to archival XMM-Newton, Chandra, and NuSTAR data from
2003, 2012, and 2013, and investigate possible spectral changes as a function
of phase over the 78d super-orbital period of this source. We find that
observations taken around phases 0.3-0.4 show very similar temperature
profiles, even though the observed flux varies significantly, while one
observation taken around phase 0 has a significantly steeper profile. We
discuss these findings in light of the recent discovery that the compact object
is a neutron star and show that precession of the accretion disk or the neutron
star can self-consistently explain most observed phenomena.Comment: 7 pages, 5 figures, submitted to ApJ; comments welcom
Mapping Digital Media: Jordan
The Mapping Digital Media project examines the global opportunities and risks created by the transition from traditional to digital media. Covering 60 countries, the project examines how these changes affect the core democratic service that any media system should provide: news about political, economic, and social affairs.With high levels of education and literacy, and a youthful population, Jordan is well-placed to explore the opportunities of digital media. Momentum for political reform was catalyzed by the regional uprisings in 2011, prompting modest concessionary measures by the authorities but also a reactionary crackdown on media freedom, with a particular focus on the internet.Television, however, remains the only universal medium in Jordan, and the past decade has seen a dramatic shift in favor of satellite as the dominant viewing platform. This has brought regional and global news providers (such as Al Jazeera), along with hundreds of other free-to-air channels, into over 90 percent of households.Digital switch-over will have little impact against this backdrop. This may explain why the authorities have been slow to prepare for the transition. At the time of writing this report, there are still no publicly available plans for switch-over, despite Jordan's international commitment to turn off analog signals by 2015
- âŠ