1,158,640 research outputs found
Si/SiC-Ceramic low process shrinkage - high temperature material for the Laser Sinter process
Actual RP-systemsare very limited in producing adequate ceramic prototypes. In the
presented process, the SiC..green part manufacturing bythe laser sintering process in combination
with special postprocessing allows the fast production of SUSiC prototypes. A mixture of SiC
powder and a reactive polymer binder system is used in the Laser Sinter process. In the following
postprocessing the porous green part has to be .infiltrated with a precursor resin, carbonised and
finally infiltrated withimolten silicon.•Incontrast to cold isostatic moulding or slip casting the
shrinkage is very low (2-4 0/0).• Experiments with suitable materials/and process conditions were
successful. This paper will show the state of and the possible further investigation into process.Mechanical Engineerin
Virtual personal assistant
Abstract This report discusses ways in which new technology could be harnessed to create an intelligent Virtual Personal Assistant (VPA) with a focus on user-based information. It will look at examples of intelligent programs with natural language processing that are currently available, with different categories of support, and examine the potential usefulness of one specific piece of software as a VPA. This engages the ability to communicate socially through natural language processing, holding (and analysing) information within the context of the user. It is suggested that new technologies may soon make the idea of virtual personal assistants a reality. Experiments conducted on this system, combined with user testing, have provided evidence that a basic program with natural language processing algorithms in the form of a VPA, with basic natural language processing and the ability to function without the need for other type of human input (or programming) may already be viable
Markovian embedding of non-Markovian superdiffusion
We consider different Markovian embedding schemes of non-Markovian stochastic
processes that are described by generalized Langevin equations (GLE) and obey
thermal detailed balance under equilibrium conditions. At thermal equilibrium
superdiffusive behavior can emerge if the total integral of the memory kernel
vanishes. Such a situation of vanishing static friction is caused by a
super-Ohmic thermal bath. One of the simplest models of ballistic
superdiffusion is determined by a bi-exponential memory kernel that was
proposed by Bao [J.-D. Bao, J. Stat. Phys. 114, 503 (2004)]. We show that this
non-Markovian model has infinitely many different 4-dimensional Markovian
embeddings. Implementing numerically the simplest one, we demonstrate that (i)
the presence of a periodic potential with arbitrarily low barriers changes the
asymptotic large time behavior from free ballistic superdiffusion into normal
diffusion; (ii) an additional biasing force renders the asymptotic dynamics
superdiffusive again. The development of transients that display a
qualitatively different behavior compared to the true large-time asymptotics
presents a general feature of this non-Markovian dynamics. These transients
though may be extremely long. As a consequence, they can be even mistaken as
the true asymptotics. We find that such intermediate asymptotics exhibit a
giant enhancement of superdiffusion in tilted washboard potentials and it is
accompanied by a giant transient superballistic current growing proportional to
with an exponent that can exceed
the ballistic value of two
Civil society in trade policy-making in Latin America: the case of the environmental movement
In recent years, and particularly perhaps since the ‘battle of Seattle’ in 1999, the issue of civil society participation in trade policy has attracted increasing policy and academic attention. Much of this attention has been drawn to the question of institutional access and channels of participation and representation within the WTO. The challenge is one that has faced other global institutions such as the World Bank and IMF for a number of years (O’Brien et al 2000).
Improving the transparency of and access to decision-making in the context of up-scaling civil society participation is not exclusively a global challenge, however. There has been a great deal of activity at the regional level around trade negotiations and increasingly in Latin America with the FTAA (Free Trade Area of the Americas) following in the wake of NAFTA (North American Free Trade Agreement) and Mercosur (Mercado Común del Sur). Few institutional reforms have been brought about without significant pressure from civil society, however. Some challenges are common to all movements attempting to participate and make their voice heard in the sensitive and traditionally closed arena of trade negotiations. But others are unique, and reflect distinct regional political histories, previous experiences of mobilisation and prevailing social and material realities. Given this, it becomes important to understand what can be learned from the experience of a globally significant region like Latin America about the possibilities and limitations of civil society participation in trade policy.
By comparing the documented experiences of NAFTA with analysis of Mercosur and the evolving FTAA negotiations, in terms of the participation of the environmental movements, important insights may be gained about: who is participating in trade policy, how and with what effect and, equally importantly, who is not participating and what are the implications of this?
The analysis will therefore attempt to identify key factors which shape these dynamics. These include;
* key strategic issues within the movements and among groups themselves (diversity of strategies, politics of coalition-building, patterns of influence and engagement/non-engagement)
* the organisation of institutional access (rights, representation, process, decision-making)
* key economic and political regional dynamics which affect each of the above (differences between and within individual countries regarding key issues and attitudes towards participation)
By comparing across different sets of trade negotiations and institutional arrangements it will be possible to identify what the key drivers and shapers of change appear to be. In other words, the extent to which these appear to derive from the nature of the institution or process itself, the strategies of the movement engaging with it, or more likely still, some combination of both these elements. The challenge is to account for diverse forms of engagement and non-engagement and, more importantly, to derive lessons from them about the possibility of constructing more effective, sustainable and transparent mechanisms of participation and representation in trade policy based on experiences to date in Latin America
- …