149 research outputs found
Process benchmarking in the fruit and vegetable supply chain
The purpose of this paper is to present the results of an international process benchmarking and to compile models of best practice business processes. The results of our international process benchmarking study allowed us to develop a framework, comprising three models, for better meeting customers’ needs. The first model presents how to understand and meet customers’ needs generally. The second model comprises those operations, work practices and business processes, which are essential in meeting customers’ needs. The third model (organisation designing model) helps the company to check, whether or not the operations, work practises and business processes of the second model can be found in and applied to the company.process benchmarking, customers’ needs, business processes, organisation designing model, Agribusiness,
A generalization of the injectivity condition for Projected Entangled Pair States
We introduce a family of tensor network states that we term semi-injective
Projected Entangled-Pair States (PEPS). They extend the class of injective PEPS
and include other states, like the ground states of the AKLT and the CZX models
in square lattices. We construct parent Hamiltonians for which semi-injective
PEPS are unique ground states. We also determine the necessary and sufficient
conditions for two tensors to generate the same family of such states in two
spatial dimensions. Using this result, we show that the third cohomology
labeling of Symmetry Protected Topological phases extends to semi-injective
PEPS.Comment: 63 page
Classification of Matrix Product States with a Local (Gauge) Symmetry
Matrix Product States (MPS) are a particular type of one dimensional tensor
network states, that have been applied to the study of numerous quantum many
body problems. One of their key features is the possibility to describe and
encode symmetries on the level of a single building block (tensor), and hence
they provide a natural playground for the study of symmetric systems. In
particular, recent works have proposed to use MPS (and higher dimensional
tensor networks) for the study of systems with local symmetry that appear in
the context of gauge theories. In this work we classify MPS which exhibit local
invariance under arbitrary gauge groups. We study the respective tensors and
their structure, revealing known constructions that follow known gauging
procedures, as well as different, other types of possible gauge invariant
states
Language Teachers and Technology : Beliefs, Attitudes, and Knowledge
This study explores language teachers’ beliefs, knowledge, and attitudes toward technology integration. Amidst the COVID-19 pandemic, language teachers were compelled to adopt various technologies for remote teaching. Our findings reveal a strong belief among teachers in the importance of technology skills for effective classroom implementation. While positive attitudes toward technology adoption were prevalent, opinions varied on its impact on teaching abilities. Teachers recognized the benefits of technology for communication and creating instructional materials. Yet, views on student engagement with technology were diverse. The findings emphasized the influence of teacher background and attitude in shaping their utilization of technology, with implications for teacher professional development and the integration of technology into educational practices.journal articl
Efficient description of many-body systems with Matrix Product Density Operators
Matrix Product States form the basis of powerful simulation methods for
ground state problems in one dimension. Their power stems from the fact that
they faithfully approximate states with a low amount of entanglement, the "area
law". In this work, we establish the mixed state analogue of this result: We
show that one-dimensional mixed states with a low amount of entanglement,
quantified by the entanglement of purification, can be efficiently approximated
by Matrix Product Density Operators (MPDOs). In combination with results
establishing area laws for thermal states, this helps to put the use of MPDOs
in the simulation of thermal states on a formal footing
Normal projected entangled pair states generating the same state
Tensor networks are generated by a set of small rank tensors and define
many-body quantum states in a succinct form. The corresponding map is not
one-to-one: different sets of tensors may generate the very same state. A
fundamental question in the study of tensor networks naturally arises: what is
then the relation between those sets? The answer to this question in one
dimensional setups has found several applications, like the characterization of
local and global symmetries, the classification of phases of matter and unitary
evolutions, or the determination of the fixed points of renormalization
procedures. Here we answer this question for projected entangled-pair states
(PEPS) in any dimension and lattice geometry, as long as the tensors generating
the states are normal, which constitute an important and generic class
High p_T Spectra of Identified Particles Produced in Pb+Pb Collisions at 158A GeV Beam Energy
Results of the NA49 collaboration on the production of hadrons with large
transverse momentum in Pb+Pb collisions at 158A GeV beam energy are presented.
A range up to p_T = 4 GeV/c is covered. The nuclear modification factor R_CP is
extracted for pions, kaons and protons, and the baryon to meson ratios p/pi+,
pbar/pi- and Lambda/K^0_s are studied. All results are compared to other
measurements at SPS and RHIC and to theoretical calculations.Comment: Submitted to J. Phys. G (Proceedings of the 9th International
Conference on Strangeness in Quark Matter, Los Angeles, USA, March 26-31,
2006). 5 pages, 3 figure
Megafloods in Europe can be anticipated from observations in hydrologically similar catchments
Megafloods that far exceed previously observed records often take citizens and experts by surprise, resulting in extremely severe damage and loss of life. Existing methods based on local and regional information rarely go beyond national borders and cannot predict these floods well because of limited data on megafloods, and because flood generation processes of extremes differ from those of smaller, more frequently observed events. Here we analyse river discharge observations from over 8,000 gauging stations across Europe and show that recent megafloods could have been anticipated from those previously observed in other places in Europe. Almost all observed megafloods (95.5%) fall within the envelope values estimated from previous floods in other similar places on the continent, implying that local surprises are not surprising at the continental scale. This holds also for older events, indicating that megafloods have not changed much in time relative to their spatial variability. The underlying concept of the study is that catchments with similar flood generation processes produce similar outliers. It is thus essential to transcend national boundaries and learn from other places across the continent to avoid surprises and save lives
Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks
A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV
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