13,636 research outputs found
Multipartite Entanglement Measures and Quantum Criticality from Matrix and Tensor Product States
We compute the multipartite entanglement measures such as the global
entanglement of various one- and two-dimensional quantum systems to probe the
quantum criticality based on the matrix and tensor product states (MPSs/TPSs).
We use infinite time-evolving block decimation (iTEBD) method to find the
ground states numerically in the form of MPSs/TPSs, and then evaluate their
entanglement measures by the method of tensor renormalization group (TRG). We
find these entanglement measures can characterize the quantum phase transitions
by their derivative discontinuity right at the critical points in all models
considered here. We also comment on the scaling behaviors of the entanglement
measures by the ideas of quantum state renormalization group transformations.Comment: 22 pages, 11 figure
Study on the non-uniform contact between the shaft-taper hole and toolholder for a high speed spindle
The drawbar mechanism of a motor built-in high speed spindle with ATC is to provide the clamping force to grip the toolholder for high speed cutting. The connection status between the shaft-taper hole and toolholder is important on the spindle design and manufacture. In this paper, contact analyses of the toolholder and shaft-taper hole using contact elements are conducted. The stresses distribution between the toolholder and shaft-taper hole is then obtained and is used for the subsequent finite element modal analysis. The finite element modal analysis results are verified by the experimental modal testing to guarantee the accuracy of finite element model. Non-uniform contact conditions between the shaft-taper hole and toolholder is addressed especially in this study. Different intensities of resistance to the cutting torque due to different clamping forces, coefficients of friction, contact types and contact rates are provided. The deformations on the shaft and toolholder are also studied in this paper. The results are helpful to design a motor built-in high speed spindle with a suitable clamping force for providing the necessary torque to resist the cutting force and to give a suggestion on the manufacture of toolholder and shaft-taper hole
Deterministic Dense Coding and Faithful Teleportation with Multipartite Graph States
We proposed novel schemes to perform the deterministic dense coding and
faithful teleportation with multipartite graph states. We also find the
sufficient and necessary condition of a viable graph state for the proposed
scheme. That is, for the associated graph, the reduced adjacency matrix of the
Tanner-type subgraph between senders and receivers should be invertible.Comment: 10 pages, 1 figure;v2. discussions improve
Effort-reward imbalance and self-rated health among Gambian healthcare professionals
Questionnaire for the Investigation of Effort-reward Imbalance and Self-rated Health among Gambian Healthcare Professionals. (DOC 616Ă‚Â kb
Effect of Samarium doping on the nucleation of fcc-Aluminum in undercooled liquids
The effect of Sm doping on the fcc-Al nucleation was investigated in Al-Sm
liquids with low Sm concentrations (xSm) with molecular dynamics simulations.
The nucleation in the moderately undercooled liquid is achieved by the recently
developed persistent-embryo method. Systematically computing the nucleation
rate with different xSm (xSm=0%, 1%, 2%, 3%, 5%) at 700 K, we found Sm dopant
reduces the nucleation rate by up to 25 orders of magnitudes with only 5%
doping concentration. This effect is mostly associated with the increase in the
free energy barrier with a minor contribution from suppression of the
attachment to the nucleus caused by Sm doping.Comment: 4 figure
ICT for Development: Two Contradictory Stories of an ICT Initiative
In this study we explore two different perspectives of one ICT project. The “mainstream” believed that an educational ICT project for Taiwanese aboriginals was successful, while the local aboriginals and local teachers did not. Using ethnographic research, we investigated the possible reasons for the disparity between the views of the mainstream and the locals. Our findings indicate that the paternalistic nature of the ICT project as well as a belief in technological supremacy contributed to the discrepancy of views regarding the success of the project. We use postcolonial theory to draw attention to the (often forgotten) voice of the aboriginals
Bridging the Digital Divide: A Case Study of Middle-age Women in Taiwan
This article reports a study of how middle-age and elder women adopt ICT through the social intervention and support from the non-profit organizations (NPOs) which they are associated with. By interviewing 30 participants of the Taiwan Women Up project, we reveal the barriers that may hinder women from learning ICT and the forces which can facilitate women in their adoption of ICT at three levels: individual, family and social group. Our findings show that, for our participants who are middle-class housewives over 40, their bonding with the NPOs serves as the main force for them to join the Taiwan Women Up project and adopt ICT. When ICT related difficulty occurs, they approach to the members of the NPOs and receive support from them while their families turn them down initially. After this project, the participants develop confidence and, accordingly, the digital divide is narrowed. Yet, there is little sign that any change of the traditional gender role has occurred
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