243 research outputs found

    Minor stars in plane graphs with minimum degree five

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    The weight of a subgraph HH in GG is the sum of the degrees in GG of vertices of HH. The {\em height} of a subgraph HH in GG is the maximum degree of vertices of HH in GG. A star in a given graph is minor if its center has degree at most five in the given graph. Lebesgue (1940) gave an approximate description of minor 55-stars in the class of normal plane maps with minimum degree five. In this paper, we give two descriptions of minor 55-stars in plane graphs with minimum degree five. By these descriptions, we can extend several results and give some new results on the weight and height for some special plane graphs with minimum degree five.Comment: 11 pages, 3 figure

    Generation of Vorticity at a Free Surface of Miscible Fluids with Different Liquid Properties

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    Ph.DDOCTOR OF PHILOSOPH

    Therapeutic efficacy of combined administration of thymosin and oxaliplatin in elderly gastric ulcer patients and its effect on cellular immunity and matrix metalloproteinase

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    Purpose: To investigate the clinical efficacy of thymosin combined with oxaliplatin and tiggio in aged gastric cancer (GC) sufferers, as well as their impact on cellular immunity and matrix metalloproteinase.Methods: Elderly GC sufferers (n = 82) were divided into study and control groups by random allocation (41 patients/group). Control group was treated with oxaliplatin combined with tiggio, while the study group was treated with thymopeptide injection, in addition to oxaliplatin combined with tiggio. Each treatment course lasted 21 days, and the study involved three courses. Clinical effectiveness and toxicity in the two groups were determined and compared before and after treatment.Results: Total effectiveness in the study group (73.16 %) and disease remission (95.11 %) were superior to the corresponding values for control patients given oxaliplatin and tiggio (48.78 and 85.37 %, respectively, p ˂ 0.05). There were markedly lower incidences of nausea, vomiting and leukopenia in the study group than in control (p ˂ 0.05).Conclusion: The use of thymosin-oxaliplatin-tigeo triple therapy for aged GC sufferers has a definite clinical benefits and low toxic side effects.Keywords: Thymosin, Asha Leigh Per, Teggio, Gastric cancer, Cellular immunity, Matrix metalloproteinas

    Emergence of Shape Bias in Convolutional Neural Networks through Activation Sparsity

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    Current deep-learning models for object recognition are known to be heavily biased toward texture. In contrast, human visual systems are known to be biased toward shape and structure. What could be the design principles in human visual systems that led to this difference? How could we introduce more shape bias into the deep learning models? In this paper, we report that sparse coding, a ubiquitous principle in the brain, can in itself introduce shape bias into the network. We found that enforcing the sparse coding constraint using a non-differential Top-K operation can lead to the emergence of structural encoding in neurons in convolutional neural networks, resulting in a smooth decomposition of objects into parts and subparts and endowing the networks with shape bias. We demonstrated this emergence of shape bias and its functional benefits for different network structures with various datasets. For object recognition convolutional neural networks, the shape bias leads to greater robustness against style and pattern change distraction. For the image synthesis generative adversary networks, the emerged shape bias leads to more coherent and decomposable structures in the synthesized images. Ablation studies suggest that sparse codes tend to encode structures, whereas the more distributed codes tend to favor texture. Our code is host at the github repository: \url{https://github.com/Crazy-Jack/nips2023_shape_vs_texture}Comment: Published as NeurIPS 2023 (Oral

    Business Value of Enterprise Micro-Blogs: Empirical Study from weibo.com in Sina

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    The increasing use of micro-blogs as marketing tools has increased the research attention on the usage and performance of enterprise micro-blogs. Based on research on information system (IS) usage and the resource-based view (RBV) theory, this study develops a model to measure the business value of enterprise micro-blogs. The model consists of metrics on micro-blog usage, micro-blog operational performance, firm capability, and performance. Questionnaires were distributed to firms that use micro-blogs. This study collects 317 valid responses for empirical analysis. The result suggests that the extent of micro-blog usage improves the operational performance of enterprise micro-blogs directly and indirectly by increasing firm capability. The operational performance of enterprise micro-blogs significantly affects firm performance. This study reveals the mechanism of business value generation of enterprise micro-blogs and extends the stream of research that combines IS usage and the RBV theory

    Noise Source Identification and Noise Directivity Analysis of Bladeless Fans by Combined CFD and CAA Method

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    The bladeless fan is a new concept of fan that does not have visible impellers. It features low noise level, uniform airflow, and improved safety. It has been widely applied in household appliances. Since the customers are particularly sensitive to the noise generated by the fan, the aeroacoustics performance of the fan needs to be accurately characterized in the design stage. In this study, computational fluid dynamic (CFD) and computational aeroacoustics (CAA) are applied to investigate the aeroacoustics performance and identify the major noise source of the bladeless fan. A prototype of the bladeless fan, including a wind channel, a base cavity, a rotor and a stator inside the base, is set in a computational domain of 4m × 2m × 2m and the airflow through the fan is simulated. The hybrid mesh is generated, the unstructured mesh in the near field, and the structured at the far field. To compute the flow field, steady RANS simulation (standard k–ε turbulence model) and Large Eddy simulation (Smagorinsky-Lilly model) are carried out. Ffowcs Williams and Hawkings (FW-H) analogy is used to predict the acoustic field. Experiments, including air velocity measurement and sound pressure measurement, are conducted to validate simulation results. Sound pressure level results at the near-field receiver illustrate that the blade passage frequency can be captured by combined CFD and CAA method. Noise source analysis shows that the combination of the rotor and stator contributes most to the noise produced by the bladeless fan. The wind channel is the secondary source. Sound pressure level contours at different distances and different heights are generated to investigate the directivity pattern of the noise generated by the bladeless fan. At the near field, the produced noise at the front and the back of the bladeless fan are louder than those at left and right; at the far field, the noise at the front is much larger than the other three sides. In addition, at the near field, with the increase of the height, two separated hotspots appear over 2,500Hz and the sound pressure level at these two hotspots increases; at the far field, the noise distribution at different heights is similar and the peak near 3,000Hz can be estimated. A possible reason to cause this peak is vortex shedding at the trailing edge of the rotor’s blades. The aeroacoustics analysis is helpful to develop strategies to reduce noise and guide the improved design of the bladeless fan
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