385 research outputs found

    Quantum phase transitional patterns in the SD-pair shell model

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    Patterns of shape-phase transition in the proton-neutron coupled systems are studied within the SDSD-pair shell model. The results show that some transitional patterns in the SDSD-pair shell model are similar to the U(5)SU(3)U(5)-SU(3), U(5)SO(6)U(5)-SO(6) transitions with signatures of the critical point symmetry of the interacting boson model.Comment: 13 pages, 7 figure

    A Review of Researches on Return Migration

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    Driven by factors related to economic development, return migration has become a topic of increasing academic interest. There are several mainstream theoretical interpretations of the phenomenon of return migration, and the existing literature focuses on the causes of return, employment choice and return effects. Through literature review, it is found that both economic factors and non-economic factors will have an impact on the decision to return. Compared with non-migrant group, returned migrants are more likely to engage in self-employed. Returned migrants may bring back advanced ideas and technologies, which will have a positive impact on local economic and social development, but the driving effect on employment is limited. In developing countries, “entrepreneurship” means vulnerability. Entrepreneurship is a choice made when all other labor market opportunities are not satisfactory or individuals have no employment opportunities, which belongs to necessity-based entrepreneurship. This paper discusses the findings based on a summary of the review and provides the prospects for future research

    Value of Autonomous Last-mile Delivery: Evidence from Alibaba

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    This paper provides the first empirical evidence of consumer responses to autonomous last-mile delivery using Alibaba\u27s recent implementation in Chinese university campuses as a case study. The study leverages customer-level data from three universities over three years, employing a difference-in-differences (DID) approach combined with dynamic matching to estimate the impact of autonomous delivery adoption on order quantities. The results reveal a significant increase in the number of orders following autonomous delivery adoption with a 21% growth. The efficiency and flexibility of autonomous vehicles reduce consumers\u27 travel costs, driving long-term usage and increased sales. However, the value of autonomous delivery diminishes when a fee is charged. The study contributes to our understanding of the value of autonomous last-mile delivery and its potential advantages over traditional courier delivery

    Evaluating Urban Heat Island Effects in Rapidly Developing Coastal Cities

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    In this chapter, we present the analysis of urban heat island (UHI) effects on coastal urban areas using satellite images as a case study in Hangzhou, China. With the sustainable development of coastal areas, land use and land cover have been dramatically changed. Such changes make the phenomenon of urban heat island (UHI) becoming serious, which has brought some negative influences on human activities or public health issues in coastal regions. This study takes Hangzhou as an example of coastal cities and uses the Landsat TM, ETM+ and OLI images to retrieve the urban land surface temperature (LST). We also mapped and compared the intensity of UHI effects in different years of 2003, 2008 and 2013. The result shows that the intensity of UHI effect in 2013 was more serious than previous years, which is increasing year by year. The study also analyzed the relationship between UHI, NDVI, and NDBI and provided some useful suggestions to mitigate the UHI effects on coastal cities such as Hangzhou in China

    Peran Daya Dukung Wilayah Terhadap Pengembangan USAha Peternakan Sapi Madura

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    Research conducted on the island of Madura. The aim of the research was analyzed the area-based development of beef cattle in Madura island. Primary research data was sourced from statistics in the Madura district in figures. Data was analyzed using Location Quotient (LQ) method. Data procesing conducted whith spreadsheet from Excel on Microsoft Windows 7. The results showed that the basis for the development of Madura cattle each regency were Pamekasan (sub-district Larangan, Pasean, Batumamar, Palengan, Proppo, Tlanakan, and Pegantenan), Sumenep (sub-district Gayam, Nonggunong and Batuputih), Bangkalan (subdistrict Kokop, Geger, Galis, Tanah Merah, and Blega) and Bangkalan (sub-district Ketapang, Sokobanah, Kedungdung, Sampang, Banyuates, Robatal, and Omben. Conclusion of the research was the development of Madura cattle concentrated in the base region of Madura cattle

    Language Prior Is Not the Only Shortcut: A Benchmark for Shortcut Learning in VQA

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    Visual Question Answering (VQA) models are prone to learn the shortcut solution formed by dataset biases rather than the intended solution. To evaluate the VQA models' reasoning ability beyond shortcut learning, the VQA-CP v2 dataset introduces a distribution shift between the training and test set given a question type. In this way, the model cannot use the training set shortcut (from question type to answer) to perform well on the test set. However, VQA-CP v2 only considers one type of shortcut and thus still cannot guarantee that the model relies on the intended solution rather than a solution specific to this shortcut. To overcome this limitation, we propose a new dataset that considers varying types of shortcuts by constructing different distribution shifts in multiple OOD test sets. In addition, we overcome the three troubling practices in the use of VQA-CP v2, e.g., selecting models using OOD test sets, and further standardize OOD evaluation procedure. Our benchmark provides a more rigorous and comprehensive testbed for shortcut learning in VQA. We benchmark recent methods and find that methods specifically designed for particular shortcuts fail to simultaneously generalize to our varying OOD test sets. We also systematically study the varying shortcuts and provide several valuable findings, which may promote the exploration of shortcut learning in VQA.Comment: Fingdings of EMNLP-202

    Unsupervised domain adaptation through transferring both the source-knowledge and target-relatedness simultaneously

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    Unsupervised domain adaptation (UDA) is an emerging research topic in the field of machine learning and pattern recognition, which aims to help the learning of unlabeled target domain by transferring knowledge from the source domain. To perform UDA, a variety of methods have been proposed, most of which concentrate on the scenario of single source and the single target domain (1S1T). However, in real applications, usually single source domain with multiple target domains are involved (1SmT), which cannot be handled directly by those 1S1T models. Unfortunately, although a few related works on 1SmT UDA have been proposed, nearly none of them model the source domain knowledge and leverage the target-relatedness jointly. To overcome these shortcomings, we herein propose a more general 1SmT UDA model through transferring both the source-knowledge and target-relatedness, UDA-SKTR for short. In this way, not only the supervision knowledge from the source domain but also the potential relatedness among the target domains are simultaneously modeled for exploitation in the process of 1SmT UDA. In addition, we construct an alternating optimization algorithm to solve the variables of the proposed model with a convergence guarantee. Finally, through extensive experiments on both benchmark and real datasets, we validate the effectiveness and superiority of the proposed method

    Direct isolation of small extracellular vesicles from human blood using viscoelastic microfluidics

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    Small extracellular vesicles (sEVs; <200 nm) that contain lipids, nucleic acids, and proteins are considered promising biomarkers for a wide variety of diseases. Conventional methods for sEV isolation from blood are incompatible with routine clinical workflows, significantly hampering the utilization of blood-derived sEVs in clinical settings. Here, we present a simple, viscoelastic-based microfluidic platform for label-free isolation of sEVs from human blood. The separation performance of the device is assessed by isolating fluorescent sEVs from whole blood, demonstrating purities and recovery rates of over 97 and 87%, respectively. Significantly, our viscoelastic-based microfluidic method also provides for a remarkable increase in sEV yield compared to gold-standard ultracentrifugation, with proteomic profiles of blood-derived sEVs purified by both methods showing similar protein compositions. To demonstrate the clinical utility of the approach, we isolate sEVs from blood samples of 20 patients with cancer and 20 healthy donors, demonstrating that elevated sEV concentrations can be observed in blood derived from patients with cancer

    Research progress in cardiotoxicity of organophosphate esters

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    Organophosphate esters (OPEs) have been extensively utilized worldwide as a substitution for brominated flame retardants. With an increased awareness of the need for environmental protection, the potential health risks and ecological hazards of OPEs have attracted widespread attention. As the dynamic organ of the circulatory system, the heart plays a significant role in maintaining normal life activities. Currently, there is a lack of systematic appraisal of the cardiotoxicity of OPEs. This article summarized the effects of OPEs on the morphological structure and physiological functions of the heart. It is found that these chemicals can lead to pericardial edema, abnormal looping, and thinning of atrioventricular walls in the heart, accompanied by alterations in heart rate, with toxic effects varying by the OPE type. These effects are primarily associated with the activation of endoplasmic reticulum stress response, the perturbation of cytoplasmic and intranuclear signal transduction pathways in cardiomyocytes. This paper provides a theoretical basis for further understanding of the toxic effects of OPEs and contributes to environmental protection and OPEs’ ecological risk assessment
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