A Note on Pseudo-Hermitian Systems with Point Interactions and Quantum Separability

We study the quantum entanglement and separability of Hermitian and pseudo-Hermitian systems of identical bosonic or fermionic particles with point interactions. The separability conditions are investigated in detail.Comment: 6 page

Calibration of a novel microstructural damage model for wire bonds

In a previous paper, a new time-domain damage-based physics model was proposed for the lifetime prediction of wire bond interconnects in power electronic modules. Unlike cycle-dependent life prediction methodologies, this model innovatively incorporates temperature- and time-dependent properties so that rate-sensitive processes associated with the bond degradation can be accurately represented. This paper presents the work on the development and calibration of the damage model by linking its core parameter, i.e., “damage,” to the strain energy density, which is a physically quantifiable materials property. Isothermal uniaxial tensile data for unbonded pure aluminum wires (99.999%) have been used to develop constitutive functions, and the model has been calibrated by the derived values of the strain energy density

Testing the molecular clock using mechanistic models of fossil preservation and molecular evolution

Molecular sequence data provide information about relative times only, and fossil-based age constraints are the ultimate source of information about absolute times in molecular clock dating analyses. Thus, fossil calibrations are critical to molecular clock dating, but competing methods are difficult to evaluate empirically because the true evolutionary time scale is never known. Here, we combine mechanistic models of fossil preservation and sequence evolution in simulations to evaluate different approaches to constructing fossil calibrations and their impact on Bayesian molecular clock dating, and the relative impact of fossil versus molecular sampling. We show that divergence time estimation is impacted by the model of fossil preservation, sampling intensity and tree shape. The addition of sequence data may improve molecular clock estimates, but accuracy and precision is dominated by the quality of the fossil calibrations. Posterior means and medians are poor representatives of true divergence times; posterior intervals provide a much more accurate estimate of divergence times, though they may be wide and often do not have high coverage probability. Our results highlight the importance of increased fossil sampling and improved statistical approaches to generating calibrations, which should incorporate the non-uniform nature of ecological and temporal fossil species distributions.ISSN:0962-8452ISSN:1471-295

Recent Results From the EU POF-PLUS Project: Multi-Gigabit Transmission Over 1 mm Core Diameter Plastic Optical Fibers

Recent activity to achieve multi-gigabit transmission over 1 mm core diameter graded-index and step-index plastic optical fibers for distances up to 50 meters is reported in this paper. By employing a simple intensity-modulated direct-detection system with pulse amplitude or digital multi-tone modulation techniques, low-cost transceivers and easy to install large-core POFs, it is demonstrated that multi-gigabit transmission up to 10 Gbit/s over 1-mm core diameter POF infrastructure is feasible. The results presented in this paper were obtained in the EU FP7 POF-PLUS project, which focused on applications in different scenarios, such as in next-generation in-building residential networks and in datacom applications

Project-based pedagogy in interdisciplinary building design adopting BIM

Purpose – This study aims to present a pedagogical practice in the project-based assessment of AEC students’ interdisciplinary building design work adopting BIM. This pedagogical practice emphasizes the impacts of BIM, as the digital collaboration platform, on the cross-disciplinary teamwork design through information sharing. This study also focuses on collecting students’ perceptions of BIM effects in integrated project design. Challenges in BIM adoption from AEC students’ perspective were identified and discussed, and could spark further research needs. Design/Methodology/Approach – Based on a thorough review of previous pedagogical practices of applying BIM in multiple AEC disciplines, this study adopted a case study of the Solar Decathlon residential building design as the group project for AEC students to deliver the design work and construction planning. In total 13 different teams within the University of Nottingham Ningbo China, each group consisting of final year undergraduate students with backgrounds in architecture, civil engineering, and architectural environmental engineering, worked to deliver the detailed design of the solar-powered residential house meeting pre-specified project objectives in terms of architectural aesthetics, structural integrity, energy efficiency, prefabrication construction techniques, and other issues such as budget and scheduling. Each team presented the cross-disciplinary design plan with cost estimate and construction scheduling together with group reports. This pedagogical study collected students’ reflective thinking on how BIM affected their design work, and compared their feedback on BIM to that from AEC industry professionals in previous studies. Findings – The case study of the Solar Decathlon building project showed the capacity of BIM in enabling interdisciplinary collaboration through information exchange and in enhancing communication across different AEC fields. More sustainable design options were considered in the early architectural design stages through the cross-disciplinary cooperation between architecture and building services engineering. BIM motivated AEC student teams to have a more comprehensive design and construction plan by considering multiple criteria including energy efficiency, budget, and construction activities. Students’ reflections indicated both positive effects of BIM (e.g., facilitating information sharing) as well as challenges for further BIM implementation, such as some architecture students’ resistance to BIM, and the lack of existing family types in the BIM library, etc. Research limitations/implications – Some limitations of the current BIM pedagogy were identified through the student group work. For example, students revealed the problem of interoperability between BIM (i.e., Autodesk Revit) and building energy simulation tools. To further integrate the university education and AEC industry practice, future BIM pedagogical work could recruit professionals and project stakeholders in the adopted case studies, for the purpose of providing professional advice on improving the constructability of the BIM-based design from student work. Originality/value – This work provides insights into the information technology applied in the AEC interdisciplinary pedagogy. Students gained the experience of a project-based collaboration and were equipped with BIM capabilities for future employment within the AEC job market. The integrated design approach was embedded throughout the team project process. Overall, this BIM pedagogical practice emphasized the link between academic activities and real-world industrial practice. The pedagogical experience gained in this BIM course could be expanded to future BIM education and research in other themes such as interoperability of building information exchange among different digital tools

Anomalous scaling and Lee-Yang zeroes in Self-Organized Criticality

We show that the generating functions of avalanche observables in SOC models exhibits a Lee-Yang phenomenon. This establishes a new link between the classical theory of critical phenomena and SOC. A scaling theory of the Lee-Yang zeroes is proposed including finite sampling effects.Comment: 33 pages, 19 figures, submitte