128 research outputs found

    Survey of Natural Language Processing for Education: Taxonomy, Systematic Review, and Future Trends

    Full text link
    Natural Language Processing (NLP) aims to analyze text or speech via techniques in the computer science field. It serves the applications in domains of healthcare, commerce, education and so on. Particularly, NLP has been widely applied to the education domain and its applications have enormous potential to help teaching and learning. In this survey, we review recent advances in NLP with the focus on solving problems relevant to the education domain. In detail, we begin with introducing the related background and the real-world scenarios in education where NLP techniques could contribute. Then, we present a taxonomy of NLP in the education domain and highlight typical NLP applications including question answering, question construction, automated assessment, and error correction. Next, we illustrate the task definition, challenges, and corresponding cutting-edge techniques based on the above taxonomy. In particular, LLM-involved methods are included for discussion due to the wide usage of LLMs in diverse NLP applications. After that, we showcase some off-the-shelf demonstrations in this domain. At last, we conclude with six promising directions for future research, including more datasets in education domain, controllable usage of LLMs, intervention of difficulty-level control, interpretable educational NLP, methods with adaptive learning, and integrated systems for education. We organize all relevant datasets and papers in the open-available Github Link for better review~\url{https://github.com/LiXinyuan1015/NLP-for-Education}

    A new method of lower extremity immobilization in radiotherapy

    Get PDF
    We developed a new method for immobilization of the fix lower extremities by using a thermoplastic mask, a carbon fiber base plate, a customized headrest, and an adjustable angle holder. The lower extremities of 11 patients with lower extremity tumors were immobilized by this method. CT simulation was performed for each patient. For all 11 patients, the device fit was suitable and comfortable and had good reproducibility, which was proven in daily radiotherapy

    miR-423-5p Inhibits Osteosarcoma Proliferation and Invasion Through Directly Targeting STMN1

    Get PDF
    Background/Aims: Increasing evidences suggest that dysregulated expression of miRNAs contributes to the progression of various tumors. However, the underlying function of miR-423-5p in osteosarcoma remains unexplored. Methods: The expression of miR-423-5p and STMN1 were determined in osteosarcoma samples and cell lines via quantitative real-time PCR. Colony formation and Cell Counting Kit-8 (CCK-8) assays were performed to measure cell proliferation ability and transwell analysis was used to detect cell invasion, and dual luciferase reporter assay was perform to analysis the interaction between the miR-423-5p and STMN1. Results: The expression levels of miR-423-5p and STMN1 in the osteosarcoma tissues and cell lines were measured by qRT-PCR. Cell viability was determined using the clone formation and CCK-8 assays. A dual-luciferase reporter and Western blot were performed to stdudy the target gene of miR-423-5p. Here, we showed that miR-423-5p expression was downregulated in osteosarcoma tissues and cell lines. However, the expression of stathmin1 (STMN1) was downregulated in osteosarcoma tissues and cell lines. Moreover, STMN1 expression level was negatively correlated with the miR-423-5p expression in the osteosarcoma tissues. We identified STMN1 was a direct target gene of miR-423-5p in osteosarcoma cell. Overexpression of miR-423-5p inhibited osteosarcoma cell proliferation, colony formation and invasion. Furthermore, we demonstrated that STMN1 was involved in miR-423-5p-mediated cell behavior such as cell proliferation, colony formation and invasion in the osteosarcoma cell. Conclusion: Our present study indicated that miR-423-5p acted as a tumor suppressor gene in osteosarcoma partly through inhibiting STMN1 expression

    ACVR1, a Therapeutic Target of Fibrodysplasia Ossificans Progressiva, Is Negatively Regulated by miR-148a

    Get PDF
    Fibrodysplasia ossificans progressiva (FOP) is a rare congenital disorder of skeletal malformations and progressive extraskeletal ossification. There is still no effective treatment for FOP. All FOP individuals harbor conserved point mutations in ACVR1 gene that are thought to cause ACVR1 constitutive activation and activate BMP signal pathway. The constitutively active ACVR1 is also found to be able to cause endothelial-to-mesenchymal transition (EndMT) in endothelial cells, which may cause the formation of FOP lesions. MicroRNAs (miRNAs) play an essential role in regulating cell differentiation. Here, we verified that miR-148a directly targeted the 3′ UTR of ACVR1 mRNA by reporter gene assays and mutational analysis at the miRNA binding sites, and inhibited ACVR1 both at the protein level and mRNA level. Further, we verified that miR-148a could inhibit the mRNA expression of the Inhibitor of DNA binding (Id) gene family thereby suppressing the BMP signaling pathway. This study suggests miR-148a is an important mediator of ACVR1, thus offering a new potential target for the development of therapeutic agents against FOP

    Outside Directors Say No: Determinants and After-Effects

    No full text

    Does independent directors’ monitoring affect reputation? Evidence from the stock and labor markets

    No full text
    Using novel data on independent directors’ opinions in China, we investigate the stock and labor market effects prompted by independent directors publicly saying “no” to major board decisions. We find that the market reacts negatively to modified director opinions, but positively to firms interlocked with the directors who said “no.” We further find substantial turnover and decline in board seats after independent directors issue modified opinions. Overall, we identify a dilemma in China whereby the labor market does not reward vigilant directors for standing up to firm insiders, although investors add a premium to effective board monitoring

    Researches on Application of GPS to Earthquake Monitoring and Prediction

    No full text
    The earliest researches on application of GPS to earthquake monitoring and prediction in China began in 1980s, and it was limited to learn some relative technology from other countries and do some test with a few of equipments. As the improvement of software for data processing and the depreciating of hardware, several local GPS network had been gradually set up till the end of 1990s, and then more systematically GPS monitoring, data processing and its application research have been done gradually. In this paper, 3 research examples of the application of GPS to earthquake monitoring and prediction are presented

    Three-Dimensional Conjugate Tooth Surface Design and Contact Analysis of Harmonic Drive with Double-Circular-Arc Tooth Profile

    No full text
    Abstract A three-dimensional conjugate tooth surface design method for Harmonic Drive with a double-circular-arc tooth profile is proposed. The radial deformation function of the flexspline (FS), obtained through Finite Element (FE) analysis, is incorporated into the kinematics model. By analyzing the FS tooth enveloping process, the optimization of the overlapping conjugate tooth profile is achieved. By utilizing the hobbing process, the three-dimensional machinable tooth surface of FS can be acquired. Utilizing the coning deformation of the FS, simulations are conducted to analyze the multi-section assembly and meshing motion of the machinable tooth surface. The FE method is utilized to analyze and compare the loaded contact characteristics. Results demonstrate that the proposed design method can achieve an internal gear pair consisting of a circular spline with a spur gear tooth surface and the FS with a machinable tooth surface. With the rated torque, approximately 24% of the FS teeth are engaged in meshing, and more than 4/5 of the tooth surface in the axial direction carries the load. The contact patterns, maximum contact pressure, and transmission error of the machinable tooth surface are 227.2%, 40.67%, and 71.24% of those on the spur gear tooth surface, respectively. It clearly demonstrates exceptional transmission performance

    Rail Corrugation of High-Speed Railway Induced by Rail Grinding

    No full text
    Rail corrugation is a common railway defect that involves diverse and complex factors. Rail grinding is also the most commonly used method to address corrugations. Through numerous irregularity tests and one-third octave frequency spectrum analyses, this study determined the characteristics and development process for rail corrugation on high-speed rail tracks. The vibration transmission properties of the grinding train were tested using the force hammer impacting method. Thereafter, using a simulation, the influence of the vertical vibration behavior of the grinding stone and the stiffness of the hydraulics were determined. Through a series of field tests and numerical simulations, this study revealed a clear correlation between rail corrugation and rail grinding and confirmed that the technical operation of rail grinding is closely associated with regular grinding marks at a wavelength of approximately 60 mm on rail surfaces. The combination of the natural vibration of the grinding stone (frequency of 60 Hz) and an inappropriate operational process can aggravate the grinding marks on the rail surfaces, thereby forming an initial excitation of rail corrugation. Although a large number of irregularity tests are performed after rail grinding, these wavelength-fixing grinding marks can cause the formation and development of rail corrugation. Suggestions for improving the high-speed rail-grinding technology are also provided

    ANALYSIS OF MESHING CHARACTERISTICS OF PIN-CYCLOID TRANSMISSION OF RV REDUCER

    No full text
    On the basis of analyzing the transmission principle and structure characteristics of the RV reducer,from the point of view of the system,considering the coupling deformation of the two stage transmission system of the RV reducer,the structure of the cycloidal gear spoke and the bearing stiffness,the analysis model of the meshing characteristic of the RV reducer is established. The meshing characteristics of the pin-cycloidal gear transmission of the RV reducer are simulated and analyzed,and the influences of the thickness of the cycloidal gear,the amount of modification and the load on the meshing characteristics are discussed in detail. At the same time,the torsional stiffness of the RV reducer is analyzed according to the analysis model established. Finally,the test of the pressure stress of the tooth root of pin wheel housing of the RV reducer and the test of the torsional stiffness are carried out. The correctness of the simulation analysis is verified
    corecore