Vehicle as a Service (VaaS): Leverage Vehicles to Build Service Networks and Capabilities for Smart Cities

Smart cities demand resources for rich immersive sensing, ubiquitous communications, powerful computing, large storage, and high intelligence (SCCSI) to support various kinds of applications, such as public safety, connected and autonomous driving, smart and connected health, and smart living. At the same time, it is widely recognized that vehicles such as autonomous cars, equipped with significantly powerful SCCSI capabilities, will become ubiquitous in future smart cities. By observing the convergence of these two trends, this article advocates the use of vehicles to build a cost-effective service network, called the Vehicle as a Service (VaaS) paradigm, where vehicles empowered with SCCSI capability form a web of mobile servers and communicators to provide SCCSI services in smart cities. Towards this direction, we first examine the potential use cases in smart cities and possible upgrades required for the transition from traditional vehicular ad hoc networks (VANETs) to VaaS. Then, we will introduce the system architecture of the VaaS paradigm and discuss how it can provide SCCSI services in future smart cities, respectively. At last, we identify the open problems of this paradigm and future research directions, including architectural design, service provisioning, incentive design, and security & privacy. We expect that this paper paves the way towards developing a cost-effective and sustainable approach for building smart cities.Comment: 32 pages, 11 figure

Study on the influencing factors of digital transformation of construction enterprises from the perspective of dual effects—a hybrid approach based on PLS-SEM and fsQCA

The digital transformation of Chinese construction enterprises is crucial for achieving sustainable and high-quality development in the construction industry. However, there is still a lack of in-depth research on the impact mechanism of digital transformation in construction enterprises. The purpose of this study is to explore the multiple influencing factors and complex causal relationships of digital transformation in construction enterprises and promote the deep integration of digitalization and construction enterprises. To this end, based on the dual-effect perspective (net effect perspective of a single influencing factor and configuration effect perspective of multiple influencing factors), using the “technology–organization–environment” framework (TOE framework) to construct a research model of influencing factors for digital transformation in construction enterprises. A sample of 236 construction enterprise managers was surveyed, and partial least squares structural equation modeling (PLS-SEM) and fuzzy set qualitative comparative analysis (fsQCA) methods were used to empirically analyze the dual effects of influencing factors for digital transformation in construction enterprises. The results show that: (1) from the net effect perspective, there are seven factors that significantly impact digital transformation in construction enterprises; (2) from the configuration effect perspective, there are three paths that can achieve high-level digital transformation in construction enterprises, and one path that leads to low-level digital transformation; (3) from the dual-effect perspective, top management support and policy support are key factors for digital transformation in Chinese construction enterprises. The research results enrich the relevant research on digital transformation in construction enterprises and provide a reference basis for promoting digital transformation in construction enterprises

Terahertz Magnon-Polaritons in TmFeO3

Magnon-polaritons are shown to play a dominant role in the propagation of terahertz (THz) waves through TmFeO3 orthoferrite, if the frequencies of the waves are in the vicinity of the quasi-antiferromagnetic spin resonance mode. Both time-domain THz transmission and emission spectroscopies reveal clear beatings between two modes with frequencies slightly above and slightly below this resonance, respectively. Rigorous modeling of the interaction between the spins of TmFeO3 and the THz light shows that the frequencies correspond to the upper and lower magnon-polariton branches. Our findings reveal the previously ignored importance of propagation effects and polaritons in such heavily debated areas as THz magnonics and THz spectroscopy of electromagnons. It also shows that future progress in these areas calls for an interdisciplinary approach at the interface between magnetism and photonics

In Situ Observation of Retained Austenite Transformation in Low-Carbon Micro-Alloyed Q&P Steels

Retained austenite (RA) transformation and its role in the mechanical properties of three low-carbon micro-alloyed quenching and partitioning (Q&P) steels was investigated utilizing in situ tensile tests and electron microscopy. Meanwhile, RA’s strain-induced martensite transformation (SIMT) was analyzed and discussed in terms of the strengthening mechanism. The results show that the ductility of the Q&P steels relies on the size and morphology of RA. In addition, both affect RA’s mechanical or thermostability. Dislocation density and carbon trapping should be considered in estimating the yield strength in the two-step Q&P process. V and Nb-Ti elements promote the formation of blocky RA. Ti accelerates the formation of film-like RA. For experimental Q&P steels with different processes and compositions, the true stress always keeps a linear relationship with the amount of transformed martensite, i.e., 30.38~46.37 MPa per vol. 1% transformed martensite, during the in situ tensile deformation

Effects of Quenching and Tempering Heat Treatment Processing on the Microstructure and Properties of High-Strength Hull Steel

The construction of heavy polar icebreakers is usually done with special hull steels, which require comprehensive properties such as good low-temperature toughness, high strength, and superior fatigue resistance. Reasonable and satisfactory heat treatments should be investigated and applied to acquire the required high strength and superior low-temperature toughness, since this is deemed an effective approach to ameliorate the combined properties of high-strength hull steels. Regarding this, the present study specifically explores the effects of different laboratory-based quenching (850 to 930◦ C) and tempering (580 to 660◦ C) heat treatments on the final low-temperature toughness of the high-strength hull steels. The low-temperature toughness is eventually improved without significantly sacrificing the strength. The results show that a favourable combination of properties can be obtained in the specimens under 900◦ C quenching and 660◦ C tempering processes. Additionality, the specimens tempered at 620◦ C present the highest hardness, owing to the higher percentage of tempered martensite. Detailed mechanisms of the enhanced properties of the typical specimens subjected to the corresponding quenching and tempering processing are analysed and explicated

Development and evaluation of a live birth prediction model for evaluating human blastocysts from a retrospective study

Background: In infertility treatment, blastocyst morphological grading is commonly used in clinical practice for blastocyst evaluation and selection, but has shown limited predictive power on live birth outcomes of blastocysts. To improve live birth prediction, a number of artificial intelligence (AI) models have been established. Most existing AI models for blastocyst evaluation only used images for live birth prediction, and the area under the receiver operating characteristic (ROC) curve (AUC) achieved by these models has plateaued at ~0.65. Methods: This study proposed a multimodal blastocyst evaluation method using both blastocyst images and patient couple’s clinical features (e.g., maternal age, hormone profiles, endometrium thickness, and semen quality) to predict live birth outcomes of human blastocysts. To utilize the multimodal data, we developed a new AI model consisting of a convolutional neural network (CNN) to process blastocyst images and a multilayer perceptron to process patient couple’s clinical features. The data set used in this study consists of 17,580 blastocysts with known live birth outcomes, blastocyst images, and patient couple’s clinical features. Results: This study achieved an AUC of 0.77 for live birth prediction, which significantly outperforms related works in the literature. Sixteen out of 103 clinical features were identified to be predictors of live birth outcomes and helped improve live birth prediction. Among these features, maternal age, the day of blastocyst transfer, antral follicle count, retrieved oocyte number, and endometrium thickness measured before transfer are the top five features contributing to live birth prediction. Heatmaps showed that the CNN in the AI model mainly focuses on image regions of inner cell mass and trophectoderm (TE) for live birth prediction, and the contribution of TE-related features was greater in the CNN trained with the inclusion of patient couple's clinical features compared with the CNN trained with blastocyst images alone. Conclusions: The results suggest that the inclusion of patient couple’s clinical features along with blastocyst images increases live birth prediction accuracy. Funding: Natural Sciences and Engineering Research Council of Canada and the Canada Research Chairs Program

Analysis of patient-reported outcomes in the approval of novel oncology drugs in the United States, 2017–2022Research in context

Summary: Background: With the growing notion of patient-focused drug development, the quality of life and other patient-reported outcomes (PROs) of cancer patients are gaining considerable attention. Several drug regulatory agencies, including the U.S. Food and Drug Administration (FDA), are calling attention to PROs. This review aims to comprehensively characterise the application of PROs and regulatory considerations for PROs in the FDA-approved novel oncology drugs. Methods: The FDA review documents and labels for novel oncology drugs approved from July 2017 to July 2022 were retrieved. We collected and analysed drug approval information, types of endpoints for PROs, PRO measures, designs of trials including PROs, and regulatory comments on PRO-related contents. Findings: Results demonstrated that PROs were used more commonly for solid tumours than hematologic malignancies, which might be correlated with the disease characteristics. We further categorised and analysed existing PRO measures, providing insight for tool selection in future oncology trial design. Our findings also indicated that PROs currently do not play a significant role in oncology drug approvals. The major deficiencies related to PROs commented on by FDA reviewers were analysed, followed by recommendations for improvements. Interpretation: This review demonstrates that PROs currently do not play a significant role in oncology drug marketing review, and how they can be used to support the approval of new oncology drugs is still in the exploratory stage. This current situation is not only related to the deficiencies in the design and implementation of PRO-related contents in oncology trials, but more importantly, it is a reminder that we should pay more attention to patient experience in the development of oncology drugs. Funding: This study was not supported by any funding

Transcriptome analysis of Sinorhizobium meliloti nodule bacteria in nifA mutant background

Tian Z, Zou H, Li J, et al. Transcriptome analysis of Sinorhizobium meliloti nodule bacteria in nifA mutant background. CHINESE SCIENCE BULLETIN. 2006;51(17):2079-2086.Gene expression profiles of a Sinorhizobium meliloti 1021 nifA mutant and wild type nodule bacteria were compared using whole genome microarrays. The results revealed a large scale alteration of gene expression (601 genes) in the nifA minus background. The loss of NifA altered the expression of many functional groups of genes (macromolecular metabolism, TCA cycle and respiration, nodulation and nitrogen fixation) and may lead to quite different life stages of the nodule bacteria. Upregulation of fixK and its associated genes was observed in the nifA mutant nodule bacteria. Additional quantitative real-time PCR experiments revealed that the transcript levels of fixLJ were significantly upshifted in the nifA mutant nodule bacteria. Putative NifA binding sites were predicted by a statistical method in the upstream sequences of 13 differentially regulated genes from the nifA transcriptome

Understanding the role of water-based nanolubricants in micro flexible rolling of aluminium

© 2020 Elsevier Ltd To comprehend the role of water-based nanolubricant in micro flexible rolling, corresponding characterisation with respect to different concentrations of nanolubricants, surface roughness variation subjected to each micro flexible rolling phase and dispersion of nanoparticles (NPs) were studied systematically. The results reveal that increasing NPs get trapped into the surfaces from the thicker zone to the thinner zone. Downward transition zone with favourable deformation features leads to the smoother surface roughness. Nanolubricants can effectively decrease rolling traces due to the beneficial nanolubrication mechanisms. Notably, the maximum reduction for rolling force is around 18% for the case under 2.0 wt% nanolubricant rolling condition. The current study provides great potential insights in how nanolubrication takes effect in microforming areas