508 research outputs found
Fusion of implementers for spinors on the circle
We consider the space of odd spinors on the circle, and a decomposition into
spinors supported on either the top or on the bottom half of the circle. If an
operator preserves this decomposition, and acts on the bottom half in the same
way as a second operator acts on the top half, then the fusion of both
operators is a third operator acting on the top half like the first, and on the
bottom half like the second. Fusion restricts to the Banach Lie group of
restricted orthogonal operators, which supports a central extension of
implementers on a Fock space. In this article, we construct a lift of fusion to
this central extension. Our construction uses Tomita-Takesaki theory for the
Clifford-von Neumann algebras of the decomposed space of spinors. Our
motivation is to obtain an operator-algebraic model for the basic central
extension of the loop group of the spin group, on which the fusion of
implementers induces a fusion product in the sense considered in the context of
transgression and string geometry. In upcoming work we will use this model to
construct a fusion product on a spinor bundle on the loop space of a string
manifold, completing a construction proposed by Stolz and Teichner.Comment: 49 page
Návrh konceptu univerzálního montážního stroje s využitím koncepce Industry 4.0
The aim of the thesis is to present the concept of the assembly device, which is based on the equipment already implemented. The concept involves deploying collaborative robots to increase the efficiency of the assembly cycle. The primary goal is to use time that is used in conventional equipment only for handling device operations. Collaborative activity reduces worker downtime, and this timeframe is significant in terms of process.Smyslem práce je představení konceptu montážního zařízení, který vychází ze zařízení již implementovaného. Koncept počítá s nasazením kolaborativních robotů pro zvýšení efektivity montážního cyklu. Primárním cílem je využití času, který je v konvenčním zařízení využit pouze pro manipulační úkony zařízení. Kolaborativní činnost redukuje prostoje pracovníka, přičemž tento časový rámec je z hlediska procesu významný
Quantum Brownian motion in a Landau level
Motivated by questions about the open-system dynamics of topological quantum
matter, we investigated the quantum Brownian motion of an electron in a
homogeneous magnetic field. When the Fermi length
becomes much longer than the magnetic length
, then the spatial coordinates of the electron
cease to commute, . As a consequence, localization of the
electron becomes limited by Heisenberg uncertainty, and the linear
bath-electron coupling becomes unconventional. Moreover, because the kinetic
energy of the electron is quenched by the strong magnetic field, the electron
has no energy to give to or take from the bath, and so the usual connection
between frictional forces and dissipation no longer holds. These two features
make quantum Brownian motion topological, in the regime , which is
at the verge of current experimental capabilities. We model topological quantum
Brownian motion in terms of an unconventional operator Langevin equation
derived from first principles, and solve this equation with the aim of
characterizing diffusion. While diffusion in the noncommutative plane turns out
to be conventional, with the mean displacement squared being proportional to
and , there is an exotic regime for the proportionality
constant in which it is directly proportional to the friction coefficient and
inversely proportional to the square of the magnetic field: in this regime,
friction helps diffusion and the magnetic field suppresses all fluctuations. We
also show that quantum tunneling can be completely suppressed in the
noncommutative plane for suitably designed metastable potential wells, a
feature that might be worth exploiting for storage and protection of quantum
information
Grassmannians of Lagrangian Polarizations
This paper is an introduction to polarizations in the symplectic and
orthogonal settings. They arise in association to a triple of compatible
structures on a real vector space, consisting of an inner product, a symplectic
form, and a complex structure. A polarization is a decomposition of the
complexified vector space into the eigenspaces of the complex structure; this
information is equivalent to the specification of a compatible triple. When
either a symplectic form or inner product is fixed, one obtains a Grassmannian
of polarizations. We give an exposition of this circle of ideas, emphasizing
the symmetry of the symplectic and orthogonal settings, and allowing the
possibility that the underlying vector spaces are infinite-dimensional. This
introduction would be useful for those interested in applications of
polarizations to representation theory, loop groups, complex geometry, moduli
spaces, quantization, and conformal field theory
Microbial protein out of thin air : fixation of nitrogen gas by an autotrophic hydrogen-oxidizing bacterial enrichment
For the production of edible microbial protein (MP), ammonia generated by the Haber-Bosch process or reclaimed ammonia from waste streams is typically considered as the nitrogen source. These processes for ammonia production are highly energy intensive. In this study, the potential for using nitrogen gas (N-2) as a direct nitrogen source for MP production by hydrogen-oxidizing bacteria (HOB) was evaluated. The use of N-2 versus ammonium as nitrogen source during the enrichment process resulted in differentiation of the bacterial community composition of the enrichments. A few previously unknown potential N-2-fixing HOB taxa (i.e., representatives of the genus Azonexus and the family Comamonadaceae) dominated the enrichments. The biomass yield of a N-2-fixing HOB enrichment was 30-50% lower than that of the ammonium-based HOB enrichment from the same inoculum source. The dried biomass of N-2-fixing HOB had a high protein content (62.0 +/- 6.3%) and an essential amino acid profile comparable to MP from ammonium-based HOB. MP from N-2-fixing HOB could potentially be produced in situ without entailing the emissions caused by ammonia production and transportation by conventional means. It could be a promising substitute for N-2-fixing protein-rich soybean because it has 70% higher protein content and double energy conversion efficiency from solar energy to biomass
Design and construction of the prototype of universal semi-automatic equipment for the automotive industry
Konštrukcia poloautomatického zariadenia DCR 231 predstavuje pre spoločnosť Mubea v dlhodobom hľadisku nákladovú úsporu, ktorá rastie s časom aktívneho využívania zariadenia. Zariadenie je koncipované ako univerzálny nástroj na automatizáciu výrobného kroku nasúvania trubičky do vnútorného priemeru trubkových stabilizátorov. Nasúvanie trubičky do oboch koncov stabilizačnej tyče prispeje k zvýšeniu pevnosti týchto koncových oblastí stabilizátora, využitie spevnenia len na koncoch stabilizačnej tyče prispieva k redukcií hmotnosti stabilizátora, ktorá čiastkovo prispieva k celkovej redukcií hmotnosti nápravy vozidla. V globálnej mierke teda zariadenie prispieva k zníženiu nákladov spojených s užívaním automobilu.Construction of semi-automatic equipment DCR 231 means for company Mubea saving money in long-range target. This economy profit rises with time period of the equipment active usage. The equipment is designed as a universal tool of automatic production step for inserting reinforcement tubes into tubular stabilizer bars. Inserting of these tubes into the both stabilizer ends brings higher strength of supported areas. Benefit of stabilizer bar reinforcement only on its ends is a lower mass leads to reduction of the whole axle mass. The equipment in global scale helps to reduce the costs connected with daily vehicle usage.
Codifying systemic design: A toolkit
In this paper we want to reflect on the use of toolkits as a codification strategy to fuel an expanding
practice of ‘systemic design’. This critical reflection is rooted in the real‐life experience of bringing
together two different sets of skills in the development of a Systemic Design Toolkit. Designers and
concept‐driven system thinkers belong to different epistemic communities. While these fields of
practice are arguably in the process of converging, in actual practice it proves to be a challenge to
transcend their governing epistemological differences. What pragmatically unites these
practitioners is their ambition to successfully codify a vast and layered knowledge base. A Systemic
Design Toolkit is argued to offer promise as a ‘boundary object’ between the epistemic
communities involved in creating the toolkit (the designers on the one hand and the conceptual
system thinkers on the other) and between the toolkit developers and toolkit users. The paper
closes with a tentative list of design criteria for systemic design toolkits
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