Spin correlated interferometry for polarized and unpolarized photons on a beam splitter

Spin interferometry of the 4th order for independent polarized as well as unpolarized photons arriving simultaneously at a beam splitter and exhibiting spin correlation while leaving it, is formulated and discussed in the quantum approach. Beam splitter is recognized as a source of genuine singlet photon states. Also, typical nonclassical beating between photons taking part in the interference of the 4th order is given a polarization dependent explanation.Comment: RevTeX, 19 pages, 1 ps figure, author web page at http://m3k.grad.hr/pavici

Understanding the Double-Level Influence of Guanxi on Construction Innovation in China: The Mediating Role of Interpersonal Knowledge Sharing and the Cross-Level Moderating Role of Inter-Organizational Relationships

Guanxi, a Chinese term that defines social networks of power and benefits, can be divided into inter-personal and inter-organizational relationships. Guanxi significantly influences construction innovation in China. Many studies have examined the relationship between guanxi and construction innovation at the project or organizational level. However, few of these studies explain how guanxi might affect an individual’s innovative behaviour from a double-level perspective. This paper builds on social capital theory and social exchange theory to examine guanxi’s role in motivating innovative behaviour in a China-specific construction context. It investigates the main effects of inter-personal relationships on innovative behaviour, the mediating effects of knowledge sharing, and the cross-level moderating effects of inter-organizational relationships. These elements were tested using a survey that received 178 responses from 35 different organizations. The results were analysed using Hierarchical Linear Modelling (HLM) and revealed that inter-personal relationships have positive influences on innovative behaviour, thus highlighting the partial mediating effects of knowledge sharing. In addition, the analyses showed that inter-organizational relationships augment inter-personal relationships and knowledge sharing on innovative behaviour by cross-level interaction. The research findings enhance an understanding of guanxi and innovative behaviour in China-specific construction project settings, as well as verifying the significance of guanxi in stimulating innovative behaviour

Power-laws in recurrence networks from dynamical systems

Recurrence networks are a novel tool of nonlinear time series analysis allowing the characterisation of higher-order geometric properties of complex dynamical systems based on recurrences in phase space, which are a fundamental concept in classical mechanics. In this Letter, we demonstrate that recurrence networks obtained from various deterministic model systems as well as experimental data naturally display power-law degree distributions with scaling exponents $\gamma$ that can be derived exclusively from the systems' invariant densities. For one-dimensional maps, we show analytically that $\gamma$ is not related to the fractal dimension. For continuous systems, we find two distinct types of behaviour: power-laws with an exponent $\gamma$ depending on a suitable notion of local dimension, and such with fixed $\gamma=1$.Comment: 6 pages, 7 figure

Scientometric analysis of BIM-based research in construction engineering and management

The purpose of this paper is to summarize the latest research of BIM adoption in construction engineering and management (CEM) and propose research directions for future scholarly work. During the recent decade, building information modeling (BIM) has gained increasing applications and research interest in the construction industry. Although there have been review-based studies that summarized BIM-based research in the overall architecture, engineering and construction (AEC) area, there is limited review that evaluates the current stage of BIM-based research specifically in the CEM sub-area. Design/methodology/approach CEM falls into the scope of AEC. It involves construction-related tasks, activities and processes (e.g. scheduling and cost estimates), issues (e.g. constructability), as well as human factors (e.g. collaboration). This study adopted a holistic literature review approach that incorporates bibliometric search and scientometric analysis. A total of 276 articles related to BIM applied in CEM were selected from Scopus as the literature sample for the scientometric analysis. Findings Some key CEM research areas (e.g. CEM pedagogy, integrated project delivery, lean and off-site construction) were identified and evaluated. Research trends in these areas were identified, and analyses were carried out with regard to how they could be integrated with BIM. For example, BIM, as a data repository for ACE facilities, has substantial potential to be integrated with a variety of other digital technologies, project delivery methods and innovative construction techniques throughout the whole process of CEM. Practical implications As BIM is one of the key technologies and digital platforms to improve the construction productivity and collaboration, it is important for industry practitioners to be updated of the latest movement and progress of the academic research. The industry, academics and governmental authorities should work with joint effort to fill the gap by first recognizing the current needs, limitations and trends of applying BIM in the construction industry. For example, it needs more understanding about how to address technical interoperability issues and how to introduce the integrated design and construction delivery approach for BIM implementation under the UK BIM Level 2/3 framework. This study contributed to the body of knowledge in BIM by proposing a framework leading to research directions including the differences of BIM effects between design-bid-build and other fast-track project delivery methods; the integration of BIM with off-site construction; and BIM pedagogy in CEM. It also addressed the need to investigate the similarities and differences between academia and industry toward perceiving the movement of BIM in construction field work

A science mapping approach based review of construction safety research

This study adopted a three-step holistic review approach consisting of bibliometric review, scientometric analysis, and in-depth discussion to gain a deeper understanding of the research development in construction safety. Focusing on a total of 513 journal articles published in Scopus, the influential journals, keywords, scholars, and articles in the domain of construction safety were analyzed

Direct reduction and extraction of iron from nickel smelting slag coupling of preparation of cementing materials using gangue composition

Aiming at the properties of Fe and SiO2 in nickel slag, the process of preparing DRI by direct reduction nickel slag from coal base was proposed, and the component of gangue is used as raw material to prepare C2S(belite) and C3S(alite), which is a comprehensive utilization of nickel slag. The reduction reaction of iron coupling of the reaction of cementitious materials was realized through thermodynamic calculation and experiment. The reduction roasting products of nickel slag with iron, C3S and C2S as the main phase were obtained by reasonable batching and temperature control technology of reduction roasting reaction

Climate applicability study of building envelopes containing phase change materials

SUMMARY Building envelopes incorporating phase change materials (PCMs) can contribute to reducing the energy consumption of buildings and enhance indoor thermal environment comfort. In this study, two building models were developed in EnergyPlus to explore the applicability of using PCMs in different climate zones. Six significantly different cities from five climate zones in China have been investigated. The simulation results reflected that for climates with small fluctuation weather conditions, PCMs with appreciate transition temperature TR can contribute to positive influences on energy saving. For example, in Guangzhou, PCMs with TR of near 26oC and 22oC contribute to the highest energy‐saving rates of 12.0% and 12.4%, for external and internal PCMs addition. And the ideal transition temperature for each climates is subjected to its own outdoor comprehensive temperatures and its indoor set temperature, for external and internal PCMs addition, respectively. For other climates with the big fluctuation weather condition, PCMs' latent heat function to the energy savings is not significant

Long-term changes in the north–south asymmetry of solar activity : a nonlinear dynamics characterization using visibility graphs

Peer reviewedPublisher PD

IoTBeholder: A Privacy Snooping Attack on User Habitual Behaviors from Smart Home Wi-Fi Traffic

With the deployment of a growing number of smart home IoT devices, privacy leakage has become a growing concern. Prior work on privacy-invasive device localization, classification, and activity identification have proven the existence of various privacy leakage risks in smart home environments. However, they only demonstrate limited threats in real world due to many impractical assumptions, such as having privileged access to the user's home network. In this paper, we identify a new end-to-end attack surface using IoTBeholder, a system that performs device localization, classification, and user activity identification. IoTBeholder can be easily run and replicated on commercial off-the-shelf (COTS) devices such as mobile phones or personal computers, enabling attackers to infer user's habitual behaviors from smart home Wi-Fi traffic alone. We set up a testbed with 23 IoT devices for evaluation in the real world. The result shows that IoTBeholder has good device classification and device activity identification performance. In addition, IoTBeholder can infer the users' habitual behaviors and automation rules with high accuracy and interpretability. It can even accurately predict the users' future actions, highlighting a significant threat to user privacy that IoT vendors and users should highly concern