| 1. |
- Antonov, A. N., et al.
(författare)
-
The electron-ion scattering experiment ELISe at the International Facility for Antiproton and Ion Research (FAIR)-A conceptual design study
- 2011
-
Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002 .- 0167-5087. ; 637:1, s. 60-76
-
Tidskriftsartikel (refereegranskat)abstract
- The electron-ion scattering experiment ELISe is part of the installations envisaged at the new experimental storage ring at the International Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany. It offers an unique opportunity to use electrons as probe in investigations of the structure of exotic nuclei. The conceptual design and the scientific challenges of ELISe are presented. (C) 2011 Elsevier B.V. All rights reserved.
|
|
| 2. |
- Barucca, G., et al.
(författare)
-
The potential of Λ and Ξ- studies with PANDA at FAIR
- 2021
-
Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:4
-
Tidskriftsartikel (refereegranskat)abstract
- The antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: p¯ p→ Λ¯ Λ and p¯ p→ Ξ¯ +Ξ-. The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA.
|
|
| 3. |
- Collaboration, The PANDA, et al.
(författare)
-
Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
- 2016
-
Ingår i: European Physical Journal A. - : Springer Publishing Company. - 1434-6001 .- 1434-601X. ; 52:10
-
Tidskriftsartikel (refereegranskat)abstract
- Simulation results for future measurements of electromagnetic proton form factors at P ¯ ANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel p¯ p→ e+e- is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e.p¯ p→ π+π-, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.
|
|
| 4. |
- Dong, Changxing, et al.
(författare)
-
Effective Heuristics for Large Euclidean TSP Instances Based on Pseudo Backbones
- 2009
-
Ingår i: Proceedings of 8th Cologne-Twente Workshop on Graphs and Combinatorial Optimization (CTW 2009). ; , s. 3-6
-
Konferensbidrag (refereegranskat)abstract
- We present two approaches for the Euclidean TSP which compute high quality tours for large instances. Both approaches are based on pseudo backbones consisting of all common edges of good tours. The first approach starts with some pre-computed good tours. Using this approach we found record tours for seven VLSI instances. The second approach is window based and constructs from scratch very good tours of huge TSPinstances, e. g., the World TSP.
|
|
| 5. |
- Dong, Changxing, et al.
(författare)
-
Effective Tour Searching for TSP by Contraction of Pseudo Backbone Edges
- 2009
-
Ingår i: Proceedings of 5th International Conference on Algorithmic Aspects in Information and Management (AAIM 2009). - Berlin-Heidelberg : Springer. ; , s. 175-187
-
Konferensbidrag (refereegranskat)abstract
- We introduce a reduction technique for the well-known TSP. The basic idea of the approach consists of transforming a TSP instance to another one with smaller size by contracting pseudo backbone edges computed in a preprocessing step, where pseudo backbone edges are edges which are likely to be in an optimal tour. A tour of the small instance can be re-transformed to a tour of the original instance. We experimentally investigated TSP benchmark instances by our reduction technique combined with the currently leading TSP heuristic of Helsgaun. The results strongly demonstrate the effectivity of this reduction technique: for the six VLSI instances xvb13584, pjh17845, fnc19402, ido21215, boa28924, and fht47608 we could set world records, i.e., find better tours than the effective reduction of the problem size so that we can search the more important tour subspace more intensively.
|
|
| 6. |
- Ernst, Christian, et al.
(författare)
-
Finding Good Tours for Huge Euclidean TSP Instances by Iterative Backbone Contraction
- 2010
-
Ingår i: Proceedings of 6th International Conference on Algorithmic Aspects in Information and Management (AAIM 2010). - Berlin-Heidelberg : Springer. - 9783642143540 - 9783642143557 ; , s. 119-130
-
Konferensbidrag (refereegranskat)abstract
- This paper presents an iterative, highly parallelizable approach to find good tours for very large instances of the Euclidian version of the well-known Traveling Salesman Problem (TSP). The basic idea of the approach consists of iteratively transforming the TSP instance to another one with smaller size by contracting pseudo backbone edges. The iteration is stopped, if the new TSP instance is small enough for directly applying an exact algorithm or an efficient TSP heuristic. The pseudo backbone edges of each iteration are computed by a window based technique in which the TSP instance is tiled in non-disjoint sub-instances. For each of these sub-instances a good tour is computed, independently of the other sub-instances. An edge which is contained in the computed tour of every sub-instance (of the current iteration) containing this edge is denoted to be a pseudo backbone edge. Paths of pseudo-backbone edges are contracted to single edges which are fixed during the subsequent process.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Heckemann, Birgit, 1969, et al.
(författare)
-
Patient and visitor aggression in healthcare: a survey exploring organizational safety culture and team efficacy.
- 2019
-
Ingår i: Journal of nursing management. - : Hindawi Limited. - 1365-2834 .- 0966-0429. ; 27:5, s. 1039-1046
-
Tidskriftsartikel (refereegranskat)abstract
- This study investigates nurse managers' perception of organizational safety culture and team efficacy, in managing patient and visitor aggression (PVA), and determines the predictors of team efficacy.PVA is a serious hazard in healthcare. A positive organizational safety culture regarding PVA enhances the safety and staff efficacy in managing PVA.A cross-sectional online survey including nurse managers in psychiatric and general hospitals (n=446) was conducted in Switzerland, Austria and Germany (November 2016 to February 2017). Data were analysed descriptively and through binary logistic regression.The key results are as follows: 'Working in a mental health setting' was 3.5 times more likely, 'consideration of the physical environment' was four times more likely, and a 'shared organizational attitude' was twice as likely to predict high team efficacy. In comparison to psychiatric hospitals, general hospital managers perceived organizational safety cultures to be less positive.A positive organizational safety culture leads to the perception that teams are more effective at managing PVA.Consideration of the physical environment and a positive shared organizational attitude regarding PVA are crucial for high team efficacy. General hospitals could benefit from approaches utilized in psychiatry to enhance staff efficacy in managing PVA. This article is protected by copyright. All rights reserved.
|
|
| 10. |
- Jäger, Gerold, et al.
(författare)
-
A backbone based TSP heuristic for large instances
- 2014
-
Ingår i: Journal of Heuristics. - : Springer Science and Business Media LLC. - 1381-1231 .- 1572-9397. ; 20:1, s. 107-124
-
Tidskriftsartikel (refereegranskat)abstract
- We introduce a reduction technique for large instances of the traveling salesman problem (TSP). This approach is based on the observation that tours with good quality are likely to share many edges. We exploit this observation by neglecting the less important tour space defined by the shared edges, and searching the important tour subspace in more depth. More precisely, by using a basic TSP heuristic, we obtain a set of starting tours. We call the set of edges which are contained in each of these starting tours as pseudo-backbone edges. Then we compute the maximal paths consisting only of pseudo-backbone edges, and transform the TSP instance to another one with smaller size by contracting each such path to a single edge. This reduced TSP instance can be investigated more intensively, and each tour of the reduced instance can be expanded to a tour of the original instance. Combining our reduction technique with the currently leading TSP heuristic of Helsgaun, we experimentally investigate 32 difficult VLSI instances from the well-known TSP homepage. In our experimental results we set world records for seven VLSI instances, i.e., find better tours than the best tours known so far (two of these world records have since been improved upon by Keld Helsgaun and Yuichi Nagata, respectively). For the remaining instances we find tours that are equally good or only slightly worse than the world record tours.
|
|
